Showing
508
question(s) for
UK Class 10
English
Q1.
How does a writer use structural choices to influence the reader?
Answer:
A writer can control the order of information, pace, paragraph length, shifts in viewpoint and changes in focus to create suspense, surprise, emphasis or emotional impact.
English
Q2.
What is the effect of juxtaposition in a text?
Answer:
Juxtaposition places contrasting ideas, characters, settings or images close together so that their differences become more noticeable and meaningful.
English
Q3.
How can a writer establish a particular perspective?
Answer:
A writer can establish perspective through narrative viewpoint, word choice, tone, description, dialogue and the amount of information given to the reader.
English
Q4.
What is semantic field and why might a writer use it?
Answer:
A semantic field is a group of words connected by meaning. Writers can use one to reinforce a theme, create an atmosphere or develop a particular idea.
English
Q5.
How does rhetorical language persuade an audience?
Answer:
Rhetorical language can appeal to emotions, logic and shared values through techniques such as repetition, rhetorical questions, direct address, contrast and carefully selected evidence.
Mathematics
Q6.
Solve the quadratic equation x² - 5x + 6 = 0.
Answer:
Factorising gives (x - 2)(x - 3) = 0. Therefore x = 2 or x = 3.
Mathematics
Q7.
What is the quadratic formula?
Answer:
For an equation ax² + bx + c = 0, the solutions are x = (-b ± √(b² - 4ac)) / 2a.
Mathematics
Q8.
What is a prime number?
Answer:
A prime number is a whole number greater than 1 that has exactly two factors: 1 and itself.
Mathematics
Q9.
What is the difference between a factor and a multiple?
Answer:
A factor divides a number exactly, while a multiple is obtained by multiplying a number by an integer.
Mathematics
Q10.
What is the highest common factor (HCF)?
Answer:
The HCF is the greatest positive integer that divides two or more numbers exactly.
Mathematics
Q11.
What is the lowest common multiple (LCM)?
Answer:
The LCM is the smallest positive integer that is a multiple of two or more numbers.
Mathematics
Q12.
What is a rational number?
Answer:
A rational number is a number that can be written as a fraction p/q, where p and q are integers and q is not zero.
Mathematics
Q13.
What is an irrational number?
Answer:
An irrational number cannot be expressed exactly as a fraction of two integers and has a non-terminating, non-repeating decimal expansion.
Mathematics
Q14.
What is standard form?
Answer:
Standard form writes a number as A × 10^n, where 1 ≤ A < 10 and n is an integer.
Mathematics
Q15.
How do you convert a percentage into a decimal?
Answer:
Divide the percentage by 100. For example, 35% becomes 0.35.
Mathematics
Q16.
How do you find a percentage of an amount?
Answer:
Convert the percentage to a decimal and multiply it by the amount.
Mathematics
Q17.
What is percentage change?
Answer:
Percentage change is calculated as change divided by the original value, multiplied by 100.
Mathematics
Q18.
What is a percentage increase?
Answer:
A percentage increase measures how much a quantity has risen relative to its original value.
Mathematics
Q19.
What is a percentage decrease?
Answer:
A percentage decrease measures how much a quantity has fallen relative to its original value.
Mathematics
Q20.
What is a ratio?
Answer:
A ratio compares two or more quantities of the same type using division.
Mathematics
Q21.
How can a ratio be simplified?
Answer:
Divide every part of the ratio by their greatest common factor.
Mathematics
Q22.
What is direct proportion?
Answer:
Two quantities are directly proportional when one is a constant multiple of the other, so their ratio remains constant.
Mathematics
Q23.
What is inverse proportion?
Answer:
Two quantities are inversely proportional when their product remains constant as one quantity increases and the other decreases.
Mathematics
Q24.
What is a recurring decimal?
Answer:
A recurring decimal is a decimal in which one or more digits repeat indefinitely.
Mathematics
Q25.
What is an index?
Answer:
An index, or exponent, indicates how many times a number or algebraic expression is multiplied by itself.
Mathematics
Q26.
What is the zero index rule?
Answer:
For any non-zero number a, a^0 = 1.
Mathematics
Q27.
What is the rule for multiplying powers with the same base?
Answer:
When multiplying powers with the same base, add their indices: a^m × a^n = a^(m+n).
Mathematics
Q28.
What is the rule for dividing powers with the same base?
Answer:
When dividing powers with the same base, subtract the indices: a^m ÷ a^n = a^(m-n).
Mathematics
Q29.
What does a negative index mean?
Answer:
A negative index represents the reciprocal of the corresponding positive power: a^-n = 1/a^n.
Mathematics
Q30.
What is a surd?
Answer:
A surd is an irrational root that cannot be simplified to a rational number.
Mathematics
Q31.
What is the difference between an expression and an equation?
Answer:
An expression represents a mathematical quantity, while an equation states that two expressions are equal.
Mathematics
Q32.
What is algebraic simplification?
Answer:
Algebraic simplification means rewriting an expression in an equivalent but simpler form by collecting like terms and applying algebraic rules.
Mathematics
Q33.
What are like terms?
Answer:
Like terms have exactly the same variables raised to the same powers and can therefore be combined.
Mathematics
Q34.
What is the distributive law?
Answer:
The distributive law states that a(b + c) = ab + ac.
Mathematics
Q35.
What does it mean to expand brackets?
Answer:
Expanding brackets means multiplying the terms outside or inside the brackets and removing the brackets using the distributive law.
Mathematics
Q36.
What does it mean to factorise an expression?
Answer:
Factorising means writing an algebraic expression as a product of simpler factors.
Mathematics
Q37.
What is a linear equation?
Answer:
A linear equation is an equation in which the highest power of the variable is one.
Mathematics
Q38.
What is a quadratic equation?
Answer:
A quadratic equation is an equation that can be written in the form ax² + bx + c = 0, where a is not zero.
Mathematics
Q39.
What is the quadratic formula?
Answer:
For ax² + bx + c = 0, the solutions are x = (-b ± √(b² - 4ac)) / 2a.
Mathematics
Q40.
What is the discriminant of a quadratic equation?
Answer:
The discriminant is b² - 4ac. It determines the number and type of solutions of a quadratic equation.
Mathematics
Q41.
What does the discriminant tell us when it is positive?
Answer:
A positive discriminant gives two distinct real solutions.
Mathematics
Q42.
What does the discriminant tell us when it is zero?
Answer:
A zero discriminant gives one repeated real solution.
Mathematics
Q43.
What does the discriminant tell us when it is negative?
Answer:
A negative discriminant means there are no real solutions.
Mathematics
Q44.
What is completing the square?
Answer:
Completing the square is a method of rewriting a quadratic expression in the form a(x - h)² + k.
Mathematics
Q45.
What is a simultaneous equation?
Answer:
A simultaneous equation is part of a system of equations that must be solved together to find common values of the variables.
Mathematics
Q46.
What is a sequence?
Answer:
A sequence is an ordered list of numbers that follows a particular rule or pattern.
Mathematics
Q47.
What is an arithmetic sequence?
Answer:
An arithmetic sequence is a sequence in which the difference between consecutive terms is constant.
Mathematics
Q48.
What is the nth term of an arithmetic sequence?
Answer:
The nth term is given by a + (n - 1)d, where a is the first term and d is the common difference.
Mathematics
Q49.
What is a geometric sequence?
Answer:
A geometric sequence is a sequence in which each term is obtained by multiplying the previous term by a constant ratio.
Mathematics
Q50.
What is a function?
Answer:
A function is a rule that assigns exactly one output to each permitted input.
Mathematics
Q51.
What is function notation?
Answer:
Function notation represents a function using a symbol such as f(x), where x is the input.
Mathematics
Q52.
What is the gradient of a straight line?
Answer:
The gradient measures the steepness of a line and is calculated as change in y divided by change in x.
Mathematics
Q53.
What is the equation of a straight line?
Answer:
A common form is y = mx + c, where m is the gradient and c is the y-intercept.
Mathematics
Q54.
What is the y-intercept?
Answer:
The y-intercept is the point where a graph crosses the y-axis.
Mathematics
Q55.
What is the gradient of a horizontal line?
Answer:
The gradient of a horizontal line is zero.
Mathematics
Q56.
What is the gradient of a vertical line?
Answer:
A vertical line has an undefined gradient because its change in x is zero.
Mathematics
Q57.
What is the equation of a circle centred at the origin?
Answer:
The equation is x² + y² = r², where r is the radius.
Mathematics
Q58.
What is Pythagoras' theorem?
Answer:
In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides: a² + b² = c².
Mathematics
Q59.
What is the hypotenuse?
Answer:
The hypotenuse is the longest side of a right-angled triangle and is opposite the right angle.
Mathematics
Q60.
What is trigonometry?
Answer:
Trigonometry is the study of relationships between angles and sides of triangles.
Mathematics
Q61.
What does SOH stand for?
Answer:
SOH represents sine = opposite ÷ hypotenuse.
Mathematics
Q62.
What does CAH stand for?
Answer:
CAH represents cosine = adjacent ÷ hypotenuse.
Mathematics
Q63.
What does TOA stand for?
Answer:
TOA represents tangent = opposite ÷ adjacent.
Mathematics
Q64.
What is the sine rule?
Answer:
The sine rule states that a/sin A = b/sin B = c/sin C for a triangle.
Mathematics
Q65.
What is the cosine rule?
Answer:
The cosine rule states that a² = b² + c² - 2bc cos A.
Mathematics
Q66.
What is the area of a triangle?
Answer:
The area of a triangle is 1/2 × base × perpendicular height.
Mathematics
Q67.
What is the area of a circle?
Answer:
The area of a circle is πr², where r is the radius.
Mathematics
Q68.
What is the circumference of a circle?
Answer:
The circumference is 2πr, where r is the radius.
Mathematics
Q69.
What is the volume of a prism?
Answer:
The volume of a prism is the area of its cross-section multiplied by its length.
Mathematics
Q70.
What is the volume of a cylinder?
Answer:
The volume of a cylinder is πr²h, where r is the radius and h is the height.
Mathematics
Q71.
What is the volume of a sphere?
Answer:
The volume of a sphere is 4/3πr³.
Mathematics
Q72.
What is the surface area of a sphere?
Answer:
The surface area of a sphere is 4πr².
Mathematics
Q73.
What is the volume of a cone?
Answer:
The volume of a cone is 1/3πr²h.
Mathematics
Q74.
What is an angle at a point?
Answer:
Angles at a point add up to 360 degrees.
Mathematics
Q75.
What is the sum of angles in a triangle?
Answer:
The interior angles of a triangle add up to 180 degrees.
Mathematics
Q76.
What is the sum of the interior angles of a quadrilateral?
Answer:
The interior angles of a quadrilateral add up to 360 degrees.
Mathematics
Q77.
What are corresponding angles?
Answer:
Corresponding angles are angles in matching positions when a transversal crosses two lines.
Mathematics
Q78.
What are alternate angles?
Answer:
Alternate angles lie on opposite sides of a transversal between two lines and are equal when the lines are parallel.
Mathematics
Q79.
What are co-interior angles?
Answer:
Co-interior angles lie on the same side of a transversal between two parallel lines and add up to 180 degrees.
Mathematics
Q80.
What is similarity in geometry?
Answer:
Similar shapes have the same shape, corresponding angles equal and corresponding sides in the same ratio.
Mathematics
Q81.
What is congruence?
Answer:
Congruent shapes have exactly the same size and shape, although they may have different orientations.
Mathematics
Q82.
What is a vector?
Answer:
A vector has both magnitude and direction and can be represented by a directed line segment.
Mathematics
Q83.
What is a scalar quantity?
Answer:
A scalar quantity has magnitude but no direction, such as mass, time or temperature.
Mathematics
Q84.
How are vectors added?
Answer:
Vectors are added by combining their corresponding components or by placing them head-to-tail geometrically.
Mathematics
Q85.
What is a translation?
Answer:
A translation moves every point of a shape by the same distance in the same direction.
Mathematics
Q86.
What is a reflection?
Answer:
A reflection produces a mirror image of a shape across a specified mirror line.
Mathematics
Q87.
What is a rotation?
Answer:
A rotation turns a shape about a fixed centre through a specified angle and direction.
Mathematics
Q88.
What is an enlargement?
Answer:
An enlargement changes the size of a shape using a scale factor while maintaining its shape.
Mathematics
Q89.
What is probability?
Answer:
Probability measures how likely an event is to occur and has values from 0 to 1.
Mathematics
Q90.
What is the probability of an impossible event?
Answer:
The probability of an impossible event is 0.
Mathematics
Q91.
What is the probability of a certain event?
Answer:
The probability of a certain event is 1.
Mathematics
Q92.
What is the complement of an event?
Answer:
The complement is the event that the original event does not occur, and P(not A) = 1 - P(A).
Mathematics
Q93.
What is an independent event?
Answer:
Two events are independent if the occurrence of one does not affect the probability of the other.
Mathematics
Q94.
What is conditional probability?
Answer:
Conditional probability is the probability of an event occurring given that another event has already occurred.
Mathematics
Q95.
What is a sample space?
Answer:
A sample space is the set of all possible outcomes of a probability experiment.
Mathematics
Q96.
What is the mean?
Answer:
The mean is calculated by adding all the values and dividing the total by the number of values.
Mathematics
Q97.
What is the median?
Answer:
The median is the middle value when a data set is arranged in order.
Mathematics
Q98.
What is the mode?
Answer:
The mode is the value that occurs most frequently in a data set.
Mathematics
Q99.
What is the range?
Answer:
The range is the difference between the largest and smallest values in a data set.
Mathematics
Q100.
What is an outlier?
Answer:
An outlier is a value that is unusually far from the other values in a data set.
Mathematics
Q101.
What is a frequency table?
Answer:
A frequency table organises data by showing each value or class and how often it occurs.
Mathematics
Q102.
What is grouped data?
Answer:
Grouped data is numerical data organised into intervals or classes rather than listing every individual value.
Mathematics
Q103.
What is a histogram?
Answer:
A histogram displays continuous grouped data using adjoining bars, with frequency represented according to class width.
Mathematics
Q104.
What is frequency density?
Answer:
Frequency density is calculated as frequency divided by class width.
Mathematics
Q105.
What is cumulative frequency?
Answer:
Cumulative frequency is the running total of frequencies up to a particular value or class boundary.
Mathematics
Q106.
What is a scatter graph?
Answer:
A scatter graph displays pairs of numerical values to investigate the relationship between two variables.
Mathematics
Q107.
What is correlation?
Answer:
Correlation describes the strength and direction of a relationship between two variables.
Mathematics
Q108.
What is positive correlation?
Answer:
Positive correlation occurs when larger values of one variable tend to be associated with larger values of the other variable.
Mathematics
Q109.
What is negative correlation?
Answer:
Negative correlation occurs when larger values of one variable tend to be associated with smaller values of the other variable.
Mathematics
Q110.
What is a line of best fit?
Answer:
A line of best fit is a line drawn through a scatter graph to represent the overall trend in the data.
Mathematics
Q111.
What is a cumulative frequency graph used for?
Answer:
A cumulative frequency graph can be used to estimate the median, quartiles, percentiles and interquartile range.
Mathematics
Q112.
What is the interquartile range?
Answer:
The interquartile range is the difference between the upper quartile and lower quartile: IQR = Q3 - Q1.
Mathematics
Q113.
What is a box plot?
Answer:
A box plot displays the minimum, lower quartile, median, upper quartile and maximum of a data set.
Mathematics
Q114.
What is the probability of an event and its complement combined?
Answer:
The probabilities of an event and its complement add to 1.
Mathematics
Q115.
What is the product rule for independent probabilities?
Answer:
For independent events A and B, the probability that both occur is P(A and B) = P(A) × P(B).
Mathematics
Q116.
What is a tree diagram?
Answer:
A tree diagram represents possible outcomes of a sequence of events and can be used to calculate probabilities.
Mathematics
Q117.
What is a bearing?
Answer:
A bearing is an angle measured clockwise from north and is normally written as a three-digit angle.
Mathematics
Q118.
What is an exact value in mathematics?
Answer:
An exact value is a value expressed without rounding, such as π, √2 or 1/3.
Mathematics
Q119.
Why is estimation useful?
Answer:
Estimation provides a quick approximate answer and helps identify whether a calculated result is reasonable.
Mathematics
Q120.
What does the discriminant tell us about a quadratic equation?
Answer:
The discriminant is b² - 4ac. If it is positive there are two distinct real solutions, if it is zero there is one repeated real solution, and if it is negative there are no real solutions.
Mathematics
Q121.
What is a direct proportion?
Answer:
Two quantities are directly proportional when one is a constant multiple of the other. Their ratio remains constant.
Mathematics
Q122.
What is the gradient of the line passing through (2, 5) and (6, 13)?
Answer:
The gradient is (13 - 5) / (6 - 2) = 8 / 4 = 2.
Mathematics
Q123.
What is the relationship between sine, cosine and tangent in a right-angled triangle?
Answer:
For an angle θ, sin θ = opposite/hypotenuse, cos θ = adjacent/hypotenuse and tan θ = opposite/adjacent.
Mathematics
Q124.
What is compound interest?
Answer:
Compound interest is interest calculated on the original amount and on interest that has already been added. The amount after n periods can be calculated using A = P(1 + r)^n when r is the interest rate per period expressed as a decimal.
Chemistry
Q125.
What is an element?
Answer:
An element is a substance made up of only one type of atom.
Chemistry
Q126.
What is an atom?
Answer:
An atom is the smallest part of an element that can exist.
Chemistry
Q127.
What is a compound?
Answer:
A compound is a substance formed when two or more different elements are chemically bonded together.
Chemistry
Q128.
What is a mixture?
Answer:
A mixture contains two or more substances that are not chemically bonded.
Chemistry
Q129.
What is a molecule?
Answer:
A molecule is a group of two or more atoms chemically bonded together.
Chemistry
Q130.
What is an isotope?
Answer:
Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.
Chemistry
Q131.
What is the atomic number?
Answer:
The atomic number is the number of protons in the nucleus of an atom.
Chemistry
Q132.
What is mass number?
Answer:
Mass number is the total number of protons and neutrons in an atom.
Chemistry
Q133.
What is an ion?
Answer:
An ion is a charged particle formed when an atom or group of atoms gains or loses electrons.
Chemistry
Q134.
What is a positive ion?
Answer:
A positive ion is formed when an atom loses one or more electrons.
Chemistry
Q135.
What is a negative ion?
Answer:
A negative ion is formed when an atom gains one or more electrons.
Chemistry
Q136.
What is the periodic table?
Answer:
The periodic table is a systematic arrangement of chemical elements according to their atomic number and properties.
Chemistry
Q137.
What is a group in the periodic table?
Answer:
A group is a vertical column in the periodic table.
Chemistry
Q138.
What is a period in the periodic table?
Answer:
A period is a horizontal row in the periodic table.
Chemistry
Q139.
What are metals?
Answer:
Metals are elements that generally conduct heat and electricity and are often shiny, malleable and ductile.
Chemistry
Q140.
What are non-metals?
Answer:
Non-metals are elements that generally have poor electrical conductivity and may be dull or brittle when solid.
Chemistry
Q141.
What is a physical change?
Answer:
A physical change changes the form or state of a substance without forming a new substance.
Chemistry
Q142.
What is a chemical change?
Answer:
A chemical change produces one or more new substances with different chemical properties.
Chemistry
Q143.
What is a chemical reaction?
Answer:
A chemical reaction is a process in which reactants are converted into new substances called products.
Chemistry
Q144.
What are reactants?
Answer:
Reactants are the substances present at the start of a chemical reaction.
Chemistry
Q145.
What are products?
Answer:
Products are the new substances formed during a chemical reaction.
Chemistry
Q146.
What is conservation of mass?
Answer:
The law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction.
Chemistry
Q147.
What is an exothermic reaction?
Answer:
An exothermic reaction releases energy to the surroundings, usually as heat.
Chemistry
Q148.
What is an endothermic reaction?
Answer:
An endothermic reaction absorbs energy from the surroundings.
Chemistry
Q149.
What is oxidation?
Answer:
Oxidation can involve the gain of oxygen, loss of hydrogen or loss of electrons.
Chemistry
Q150.
What is reduction?
Answer:
Reduction can involve the loss of oxygen, gain of hydrogen or gain of electrons.
Chemistry
Q151.
What is redox?
Answer:
A redox reaction is a reaction in which oxidation and reduction occur together.
Chemistry
Q152.
What is an acid?
Answer:
An acid is a substance that produces hydrogen ions in aqueous solution.
Chemistry
Q153.
What is an alkali?
Answer:
An alkali is a soluble base that produces hydroxide ions in aqueous solution.
Chemistry
Q154.
What is a base?
Answer:
A base is a substance that can neutralise an acid.
Chemistry
Q155.
What is neutralisation?
Answer:
Neutralisation is a reaction between an acid and a base that produces salt and water.
Chemistry
Q156.
What is the pH scale?
Answer:
The pH scale measures how acidic or alkaline an aqueous solution is.
Chemistry
Q157.
What does a pH below 7 indicate?
Answer:
A pH below 7 indicates an acidic solution.
Chemistry
Q158.
What does a pH of 7 indicate?
Answer:
A pH of 7 indicates a neutral solution at standard conditions.
Chemistry
Q159.
What does a pH above 7 indicate?
Answer:
A pH above 7 indicates an alkaline solution.
Chemistry
Q160.
What is an indicator?
Answer:
An indicator is a substance that changes colour depending on the acidity or alkalinity of a solution.
Chemistry
Q161.
What is litmus?
Answer:
Litmus is an indicator that turns red in acidic solutions and blue in alkaline solutions.
Chemistry
Q162.
What is a universal indicator?
Answer:
A universal indicator is a mixture of indicators that gives different colours across a range of pH values.
Chemistry
Q163.
What is a salt?
Answer:
A salt is an ionic compound formed when the hydrogen ions of an acid are replaced by metal ions or ammonium ions.
Chemistry
Q164.
What is electrolysis?
Answer:
Electrolysis is the decomposition of an ionic compound using electricity when it is molten or dissolved in water.
Chemistry
Q165.
What is an electrolyte?
Answer:
An electrolyte is a substance containing mobile ions that conducts electricity when molten or dissolved in water.
Chemistry
Q166.
What happens at the cathode during electrolysis?
Answer:
Positive ions move towards the cathode and gain electrons in reduction reactions.
Chemistry
Q167.
What happens at the anode during electrolysis?
Answer:
Negative ions move towards the anode and lose electrons in oxidation reactions.
Chemistry
Q168.
What is a catalyst?
Answer:
A catalyst increases the rate of a reaction without being used up overall.
Chemistry
Q169.
How does a catalyst increase reaction rate?
Answer:
A catalyst provides an alternative reaction pathway with a lower activation energy.
Chemistry
Q170.
What is activation energy?
Answer:
Activation energy is the minimum energy required for a reaction to occur.
Chemistry
Q171.
What factors affect the rate of a reaction?
Answer:
Temperature, concentration, pressure for gases, surface area and catalysts can affect reaction rate.
Chemistry
Q172.
How does temperature affect reaction rate?
Answer:
Increasing temperature usually increases reaction rate because particles move faster and collide more frequently with sufficient energy.
Chemistry
Q173.
How does concentration affect reaction rate?
Answer:
Increasing concentration usually increases reaction rate because there are more reactant particles per unit volume.
Chemistry
Q174.
How does surface area affect reaction rate?
Answer:
Increasing surface area usually increases reaction rate because more particles are exposed for collisions.
Chemistry
Q175.
What is collision theory?
Answer:
Collision theory states that particles must collide with sufficient energy and suitable orientation for a reaction to occur.
Chemistry
Q176.
What is a reversible reaction?
Answer:
A reversible reaction can proceed in both the forward and backward directions.
Chemistry
Q177.
What is dynamic equilibrium?
Answer:
Dynamic equilibrium occurs in a closed system when the forward and reverse reactions occur at equal rates.
Chemistry
Q178.
What is Le Chatelier's principle?
Answer:
It states that a system at equilibrium responds to a change in conditions by opposing the change.
Chemistry
Q179.
What is an ionic bond?
Answer:
An ionic bond is the strong electrostatic attraction between oppositely charged ions.
Chemistry
Q180.
What is covalent bonding?
Answer:
Covalent bonding involves the sharing of pairs of electrons between atoms.
Chemistry
Q181.
What is metallic bonding?
Answer:
Metallic bonding is the electrostatic attraction between positive metal ions and delocalised electrons.
Chemistry
Q182.
Why do ionic compounds have high melting points?
Answer:
Ionic compounds have strong electrostatic attractions between oppositely charged ions that require a lot of energy to overcome.
Chemistry
Q183.
Why do metals conduct electricity?
Answer:
Metals contain delocalised electrons that can move through the structure and carry electrical charge.
Chemistry
Q184.
Why do simple molecular substances have low boiling points?
Answer:
They have weak intermolecular forces that require relatively little energy to overcome.
Chemistry
Q185.
What is a giant covalent structure?
Answer:
It is a large structure in which atoms are joined by many strong covalent bonds.
Chemistry
Q186.
What is diamond?
Answer:
Diamond is a giant covalent form of carbon in which each carbon atom is bonded to four other carbon atoms.
Chemistry
Q187.
What is graphite?
Answer:
Graphite is a giant covalent form of carbon made of layers of carbon atoms with delocalised electrons.
Chemistry
Q188.
Why is diamond very hard?
Answer:
Each carbon atom is strongly covalently bonded to four other carbon atoms in a rigid three-dimensional structure.
Chemistry
Q189.
Why can graphite conduct electricity?
Answer:
Graphite has delocalised electrons that can move along its layers.
Chemistry
Q190.
What is crude oil?
Answer:
Crude oil is a mixture of hydrocarbons formed from the remains of ancient organisms over millions of years.
Chemistry
Q191.
What is a hydrocarbon?
Answer:
A hydrocarbon is a compound containing only carbon and hydrogen atoms.
Chemistry
Q192.
What is fractional distillation?
Answer:
Fractional distillation separates crude oil into fractions according to their different boiling points.
Chemistry
Q193.
What is an alkane?
Answer:
An alkane is a saturated hydrocarbon containing only single carbon-carbon bonds.
Chemistry
Q194.
What is the general formula of alkanes?
Answer:
The general formula for alkanes is CnH2n+2.
Chemistry
Q195.
What is an alkene?
Answer:
An alkene is an unsaturated hydrocarbon containing at least one carbon-carbon double bond.
Chemistry
Q196.
What is the general formula of alkenes?
Answer:
The general formula for alkenes with one double bond is CnH2n.
Chemistry
Q197.
How can an alkene be tested?
Answer:
An alkene can be tested using bromine water, which changes from orange to colourless.
Chemistry
Q198.
What is combustion?
Answer:
Combustion is a reaction in which a substance reacts with oxygen and releases energy.
Chemistry
Q199.
What are the products of complete combustion of a hydrocarbon?
Answer:
Complete combustion of a hydrocarbon produces carbon dioxide and water.
Chemistry
Q200.
What causes incomplete combustion?
Answer:
Incomplete combustion occurs when there is insufficient oxygen.
Chemistry
Q201.
Why is carbon monoxide dangerous?
Answer:
Carbon monoxide is poisonous because it reduces the blood's ability to carry oxygen.
Chemistry
Q202.
What is cracking?
Answer:
Cracking breaks long-chain hydrocarbons into smaller, more useful hydrocarbons.
Chemistry
Q203.
Why is cracking useful?
Answer:
Cracking produces shorter-chain alkanes for fuels and alkenes for making polymers.
Chemistry
Q204.
What is a polymer?
Answer:
A polymer is a very large molecule made from many repeating monomer units.
Chemistry
Q205.
What is a monomer?
Answer:
A monomer is a small molecule that can join with other monomers to form a polymer.
Chemistry
Q206.
What is addition polymerisation?
Answer:
Addition polymerisation joins unsaturated monomers together to form a polymer without producing another small molecule.
Chemistry
Q207.
What is a homologous series?
Answer:
A homologous series is a family of compounds with the same functional group and similar chemical properties.
Chemistry
Q208.
What is ethanol?
Answer:
Ethanol is an alcohol with the formula C2H5OH.
Chemistry
Q209.
How is ethanol produced by fermentation?
Answer:
Yeast converts glucose into ethanol and carbon dioxide under anaerobic conditions.
Chemistry
Q210.
What conditions are needed for fermentation?
Answer:
Fermentation requires yeast, a suitable temperature and the absence of oxygen.
Chemistry
Q211.
What is oxidation of ethanol?
Answer:
Ethanol can be oxidised to ethanoic acid, for example during the production of vinegar.
Chemistry
Q212.
What is ethanoic acid?
Answer:
Ethanoic acid is a carboxylic acid with the formula CH3COOH.
Chemistry
Q213.
What is an ester?
Answer:
An ester is an organic compound commonly formed when an alcohol reacts with a carboxylic acid.
Chemistry
Q214.
What is the general reaction between an alcohol and carboxylic acid?
Answer:
An alcohol reacts with a carboxylic acid to form an ester and water.
Chemistry
Q215.
What is a fertiliser?
Answer:
A fertiliser is a substance added to soil to provide essential mineral ions needed by plants.
Chemistry
Q216.
Why do plants need nitrates?
Answer:
Plants need nitrate ions to make amino acids and proteins for growth.
Chemistry
Q217.
What is potable water?
Answer:
Potable water is water that has been treated so that it is safe to drink.
Chemistry
Q218.
How can drinking water be obtained from fresh water?
Answer:
Fresh water can be treated by filtration and sterilisation to remove unwanted substances and microorganisms.
Chemistry
Q219.
What is filtration?
Answer:
Filtration separates an insoluble solid from a liquid using a filter.
Chemistry
Q220.
What is crystallisation?
Answer:
Crystallisation is used to obtain a soluble solid from a solution by forming crystals as the solvent is removed or the solution cools.
Chemistry
Q221.
What is chromatography?
Answer:
Chromatography separates substances in a mixture because they travel through a medium at different rates.
Chemistry
Q222.
What is the purpose of a chromatogram?
Answer:
A chromatogram shows the separated components of a mixture and can help identify substances.
Chemistry
Q223.
What is a pure substance?
Answer:
A pure substance contains only one element or one compound and has a fixed composition.
Chemistry
Q224.
How can purity be checked using melting point?
Answer:
A pure substance has a sharp melting point, while impurities usually cause melting to occur over a range and lower the melting point.
Chemistry
Q225.
What is relative formula mass?
Answer:
Relative formula mass is the sum of the relative atomic masses of all atoms shown in a chemical formula.
Chemistry
Q226.
What is the mole?
Answer:
A mole is the amount of substance containing approximately 6.02 × 10²³ particles.
Chemistry
Q227.
What is Avogadro's constant?
Answer:
Avogadro's constant is approximately 6.02 × 10²³ particles per mole.
Chemistry
Q228.
How is the number of moles calculated from mass?
Answer:
Number of moles equals mass in grams divided by relative formula mass.
Chemistry
Q229.
What is concentration?
Answer:
Concentration describes the amount of solute dissolved in a given volume of solution.
Chemistry
Q230.
What is the concentration formula in mol/dm³?
Answer:
Concentration equals the number of moles divided by the volume in dm³.
Chemistry
Q231.
What is percentage yield?
Answer:
Percentage yield compares the actual amount of product obtained with the theoretical maximum amount.
Chemistry
Q232.
Why can the percentage yield be less than 100 percent?
Answer:
Yield can be below 100 percent because reactions may be incomplete, products may be lost during separation, or side reactions may occur.
Chemistry
Q233.
What is atom economy?
Answer:
Atom economy measures how efficiently the atoms in the reactants are converted into the desired product.
Chemistry
Q234.
Why is high atom economy desirable?
Answer:
High atom economy reduces waste and makes chemical processes more efficient and sustainable.
Biology
Q235.
What is the basic unit of life?
Answer:
The cell is the basic structural and functional unit of life.
Biology
Q236.
What is the function of the nucleus?
Answer:
The nucleus contains genetic material and controls the activities of the cell.
Biology
Q237.
What is the function of mitochondria?
Answer:
Mitochondria are the site of aerobic respiration and release energy for cellular activities.
Biology
Q238.
What is the function of ribosomes?
Answer:
Ribosomes are the sites of protein synthesis.
Biology
Q239.
What is diffusion?
Answer:
Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.
Biology
Q240.
What is osmosis?
Answer:
Osmosis is the net movement of water molecules through a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
Biology
Q241.
What is active transport?
Answer:
Active transport is the movement of substances against a concentration gradient using energy released by respiration.
Biology
Q242.
What is a tissue?
Answer:
A tissue is a group of similar cells working together to perform a particular function.
Biology
Q243.
What is an organ?
Answer:
An organ is a group of different tissues working together to perform a particular function.
Biology
Q244.
What is an organ system?
Answer:
An organ system is a group of organs working together to carry out a major function.
Biology
Q245.
What is an enzyme?
Answer:
An enzyme is a biological catalyst that speeds up chemical reactions without being used up.
Biology
Q246.
What is the active site of an enzyme?
Answer:
The active site is the region of an enzyme where the substrate binds and the reaction occurs.
Biology
Q247.
How does temperature affect enzyme activity?
Answer:
Increasing temperature generally increases enzyme activity up to an optimum, after which the enzyme may denature and activity decreases.
Biology
Q248.
What is denaturation?
Answer:
Denaturation is a change in an enzyme's structure that alters its active site and prevents the substrate from binding effectively.
Biology
Q249.
What is photosynthesis?
Answer:
Photosynthesis is the process by which plants use light energy to convert carbon dioxide and water into glucose, releasing oxygen.
Biology
Q250.
Where does photosynthesis take place?
Answer:
Photosynthesis takes place mainly in the chloroplasts of plant cells.
Biology
Q251.
What is chlorophyll?
Answer:
Chlorophyll is the green pigment that absorbs light energy for photosynthesis.
Biology
Q252.
What are the raw materials for photosynthesis?
Answer:
The raw materials are carbon dioxide and water.
Biology
Q253.
What factors can limit the rate of photosynthesis?
Answer:
Light intensity, carbon dioxide concentration and temperature can limit the rate of photosynthesis.
Biology
Q254.
What is aerobic respiration?
Answer:
Aerobic respiration is the chemical process that releases energy from glucose using oxygen.
Biology
Q255.
Where does aerobic respiration mainly occur?
Answer:
Aerobic respiration mainly occurs in the mitochondria.
Biology
Q256.
What is anaerobic respiration in humans?
Answer:
Anaerobic respiration in humans releases energy from glucose without oxygen and produces lactic acid.
Biology
Q257.
Why does breathing rate increase during exercise?
Answer:
Breathing rate increases to supply more oxygen and remove more carbon dioxide as the muscles respire faster.
Biology
Q258.
What is the function of red blood cells?
Answer:
Red blood cells transport oxygen around the body using haemoglobin.
Biology
Q259.
What is the function of haemoglobin?
Answer:
Haemoglobin binds with oxygen in red blood cells and transports it around the body.
Biology
Q260.
What is the function of white blood cells?
Answer:
White blood cells defend the body against pathogens.
Biology
Q261.
What is the function of platelets?
Answer:
Platelets help blood clot and prevent excessive blood loss.
Biology
Q262.
What is the function of plasma?
Answer:
Plasma is the liquid part of blood that transports cells and dissolved substances.
Biology
Q263.
What is the function of the heart?
Answer:
The heart pumps blood around the body.
Biology
Q264.
What is double circulation?
Answer:
Double circulation means that blood passes through the heart twice during one complete circuit of the body.
Biology
Q265.
What is the role of arteries?
Answer:
Arteries carry blood away from the heart.
Biology
Q266.
What is the role of veins?
Answer:
Veins carry blood towards the heart.
Biology
Q267.
What is the role of capillaries?
Answer:
Capillaries allow substances to exchange between the blood and body tissues.
Biology
Q268.
Why do capillaries have thin walls?
Answer:
Their thin walls provide a short diffusion distance for rapid exchange of substances.
Biology
Q269.
What is the function of the lungs?
Answer:
The lungs are the main organs of gas exchange, allowing oxygen to enter the blood and carbon dioxide to leave it.
Biology
Q270.
What happens in the alveoli?
Answer:
Oxygen diffuses from the air in the alveoli into the blood, while carbon dioxide diffuses from the blood into the alveoli.
Biology
Q271.
How are alveoli adapted for gas exchange?
Answer:
They have a large surface area, thin walls, a good blood supply and a moist surface.
Biology
Q272.
What is homeostasis?
Answer:
Homeostasis is the maintenance of a stable internal environment despite changes in external conditions.
Biology
Q273.
What is negative feedback?
Answer:
Negative feedback is a control mechanism in which a change triggers responses that reduce or reverse the original change.
Biology
Q274.
How does the body regulate temperature when it is too hot?
Answer:
The body increases heat loss through processes such as sweating and increased blood flow near the skin.
Biology
Q275.
How does the body respond when it is too cold?
Answer:
The body reduces heat loss and increases heat production through mechanisms such as vasoconstriction and shivering.
Biology
Q276.
What is insulin?
Answer:
Insulin is a hormone produced by the pancreas that helps reduce blood glucose concentration.
Biology
Q277.
What happens when blood glucose concentration rises?
Answer:
The pancreas releases insulin, causing cells to take up more glucose and the liver to store glucose as glycogen.
Biology
Q278.
What is diabetes?
Answer:
Diabetes is a condition in which blood glucose regulation is impaired.
Biology
Q279.
What is a hormone?
Answer:
A hormone is a chemical messenger released by a gland and transported in the blood to target organs.
Biology
Q280.
What is the nervous system?
Answer:
The nervous system coordinates responses to stimuli using electrical impulses and chemical signals.
Biology
Q281.
What is a reflex action?
Answer:
A reflex action is a rapid, automatic response to a stimulus that helps protect the body.
Biology
Q282.
What is a synapse?
Answer:
A synapse is a junction between two neurons where signals are transmitted using neurotransmitters.
Biology
Q283.
What is a stimulus?
Answer:
A stimulus is a change in the internal or external environment that can be detected by an organism.
Biology
Q284.
What is a receptor?
Answer:
A receptor is a specialised cell or group of cells that detects a stimulus.
Biology
Q285.
What is reproduction?
Answer:
Reproduction is the biological process by which organisms produce offspring.
Biology
Q286.
What is sexual reproduction?
Answer:
Sexual reproduction involves the fusion of male and female gametes and produces genetically varied offspring.
Biology
Q287.
What is asexual reproduction?
Answer:
Asexual reproduction involves one parent and produces genetically similar offspring.
Biology
Q288.
What is a gamete?
Answer:
A gamete is a reproductive cell containing a single set of chromosomes.
Biology
Q289.
What is fertilisation?
Answer:
Fertilisation is the fusion of male and female gametes to form a zygote.
Biology
Q290.
What is a chromosome?
Answer:
A chromosome is a long DNA molecule associated with proteins and containing genetic information.
Biology
Q291.
What is DNA?
Answer:
DNA is the molecule that carries genetic information in living organisms.
Biology
Q292.
What is a gene?
Answer:
A gene is a section of DNA that contains instructions for a particular characteristic or functional product.
Biology
Q293.
What is an allele?
Answer:
An allele is an alternative version of a gene.
Biology
Q294.
What is a dominant allele?
Answer:
A dominant allele is expressed in the phenotype when at least one copy is present.
Biology
Q295.
What is a recessive allele?
Answer:
A recessive allele is expressed in the phenotype only when two copies are present in a typical simple inheritance pattern.
Biology
Q296.
What is a mutation?
Answer:
A mutation is a change in the DNA base sequence of an organism.
Biology
Q297.
How can mutations affect organisms?
Answer:
Mutations can have no effect, produce harmful effects, or sometimes produce beneficial variations.
Biology
Q298.
What is mitosis?
Answer:
Mitosis is cell division that produces two genetically identical daughter cells with the same chromosome number as the parent cell.
Biology
Q299.
What is meiosis?
Answer:
Meiosis is a type of cell division that produces genetically varied haploid gametes.
Biology
Q300.
Why is meiosis important?
Answer:
Meiosis produces haploid gametes and introduces genetic variation through processes such as independent assortment and recombination.
Biology
Q301.
What is genetic variation?
Answer:
Genetic variation is the difference in genetic characteristics between individuals of the same species.
Biology
Q302.
What is natural selection?
Answer:
Natural selection is the process in which individuals with advantageous inherited characteristics are more likely to survive and reproduce.
Biology
Q303.
What is evolution?
Answer:
Evolution is the change in inherited characteristics of populations over generations.
Biology
Q304.
What is adaptation?
Answer:
An adaptation is an inherited feature that improves an organism's ability to survive and reproduce in its environment.
Biology
Q305.
What is a species?
Answer:
A species is a group of organisms that can reproduce with one another to produce fertile offspring.
Biology
Q306.
What is biodiversity?
Answer:
Biodiversity is the variety of different species and living organisms within an ecosystem or on Earth.
Biology
Q307.
What is an ecosystem?
Answer:
An ecosystem consists of a community of organisms interacting with each other and with their physical environment.
Biology
Q308.
What is a food chain?
Answer:
A food chain shows the transfer of energy and biomass from one organism to another through feeding.
Biology
Q309.
What is a producer?
Answer:
A producer is an organism that makes its own organic food, usually through photosynthesis.
Biology
Q310.
What is a consumer?
Answer:
A consumer is an organism that obtains energy by feeding on other organisms.
Biology
Q311.
What is a decomposer?
Answer:
A decomposer breaks down dead organic material and releases nutrients back into the ecosystem.
Biology
Q312.
Why does energy decrease along a food chain?
Answer:
Energy is lost through respiration, movement, heat and waste, so less energy is available at higher trophic levels.
Biology
Q313.
What is a trophic level?
Answer:
A trophic level is a feeding position occupied by an organism in a food chain or food web.
Biology
Q314.
What is a food web?
Answer:
A food web shows how several interconnected food chains operate within an ecosystem.
Biology
Q315.
What is a pathogen?
Answer:
A pathogen is a microorganism or biological agent that can cause disease.
Biology
Q316.
What are bacteria?
Answer:
Bacteria are single-celled microorganisms that can be beneficial, harmless or pathogenic.
Biology
Q317.
What are viruses?
Answer:
Viruses are infectious particles that reproduce inside living cells using the host cell's machinery.
Biology
Q318.
How does vaccination protect against disease?
Answer:
Vaccination exposes the immune system to antigens so that it can develop memory cells and respond rapidly to the pathogen later.
Biology
Q319.
What are antibodies?
Answer:
Antibodies are proteins produced by immune cells that bind specifically to antigens.
Biology
Q320.
What are antibiotics?
Answer:
Antibiotics are medicines used to treat bacterial infections by killing bacteria or preventing their growth.
Biology
Q321.
Why do antibiotics not normally work against viruses?
Answer:
Antibiotics target structures or processes found in bacteria, which viruses do not possess in the same way.
Biology
Q322.
What is antibiotic resistance?
Answer:
Antibiotic resistance occurs when bacteria evolve characteristics that allow them to survive treatment with antibiotics.
Biology
Q323.
What is selective breeding?
Answer:
Selective breeding is the process of choosing parents with desirable characteristics and breeding them to increase those characteristics in offspring.
Biology
Q324.
What is genetic engineering?
Answer:
Genetic engineering involves changing an organism's genetic material by inserting, removing or altering genes.
Biology
Q325.
What is cloning?
Answer:
Cloning is the production of genetically identical cells or organisms from a single original source.
Biology
Q326.
What is a stem cell?
Answer:
A stem cell is an undifferentiated cell that can divide and develop into specialised cell types.
Biology
Q327.
What is transpiration?
Answer:
Transpiration is the loss of water vapour from plant leaves, mainly through stomata.
Biology
Q328.
What is the function of xylem?
Answer:
Xylem transports water and mineral ions from the roots to the rest of the plant.
Biology
Q329.
What is the function of phloem?
Answer:
Phloem transports dissolved sugars and other organic substances around the plant.
Biology
Q330.
What are stomata?
Answer:
Stomata are small pores in plant leaves that allow gas exchange and control water loss.
Biology
Q331.
What is pollination?
Answer:
Pollination is the transfer of pollen from the anther to the stigma of a flower.
Biology
Q332.
What is fertilisation in flowering plants?
Answer:
Fertilisation occurs when the male gamete from pollen fuses with the female gamete in the ovule.
Biology
Q333.
What is a reflex arc?
Answer:
A reflex arc is the pathway followed by nerve impulses during a reflex response, involving a receptor, sensory neuron, relay neuron and motor neuron.
Biology
Q334.
How do muscles cause movement?
Answer:
Muscles contract and relax, often working in antagonistic pairs, to move bones at joints.
Biology
Q335.
What is a synovial joint?
Answer:
A synovial joint is a freely movable joint containing structures such as cartilage, synovial fluid and ligaments.
Biology
Q336.
Why is cartilage present at the ends of bones in joints?
Answer:
Cartilage reduces friction and absorbs shock between the bones.
Biology
Q337.
What is a balanced diet?
Answer:
A balanced diet provides the correct amounts of nutrients and energy needed for health and normal body functions.
Biology
Q338.
Why is glucose important to cells?
Answer:
Glucose is an important respiratory substrate that can be broken down to release energy.
Biology
Q339.
What is the role of bile in digestion?
Answer:
Bile neutralises stomach acid and emulsifies fats, increasing the surface area available for lipase action.
Biology
Q340.
What is the function of the small intestine?
Answer:
The small intestine completes digestion and absorbs soluble products of digestion into the blood.
Biology
Q341.
How is the small intestine adapted for absorption?
Answer:
It has many villi and microvilli, providing a large surface area, with thin walls and a good blood supply.
Biology
Q342.
What is excretion?
Answer:
Excretion is the removal of metabolic waste products and substances present in excess from the body.
Biology
Q343.
What is the main function of the kidneys?
Answer:
The kidneys filter the blood, remove nitrogenous waste and help regulate water and ion levels.
Biology
Q344.
What is selective reabsorption?
Answer:
Selective reabsorption is the process by which useful substances such as glucose, ions and appropriate amounts of water are returned from the kidney tubule to the blood.
Biology
Q345.
What is the role of ADH?
Answer:
ADH increases the permeability of kidney collecting ducts to water, helping the body conserve water.
Biology
Q346.
What is the role of the placenta?
Answer:
The placenta allows exchange of oxygen, nutrients and waste products between the mother and developing fetus without direct mixing of their blood.
Biology
Q347.
What is puberty?
Answer:
Puberty is the period when hormonal changes lead to sexual maturity and the development of secondary sexual characteristics.
Biology
Q348.
What is the menstrual cycle?
Answer:
The menstrual cycle is a recurring sequence of hormonal and reproductive changes preparing the female reproductive system for possible pregnancy.
Biology
Q349.
What is ovulation?
Answer:
Ovulation is the release of a mature egg cell from an ovary.
Biology
Q350.
What is implantation?
Answer:
Implantation is the attachment of an early embryo to the lining of the uterus.
Biology
Q351.
Why is genetic variation important for natural selection?
Answer:
Genetic variation provides differences between individuals, allowing natural selection to favour inherited characteristics that improve survival and reproduction.
Biology
Q352.
How can human activities reduce biodiversity?
Answer:
Activities such as habitat destruction, pollution, overfishing, deforestation and climate change can reduce biodiversity.
Biology
Q353.
What is conservation?
Answer:
Conservation is the protection and management of species, habitats and natural resources to maintain biodiversity.
Science
Q354.
What is the difference between mitosis and meiosis?
Answer:
Mitosis produces genetically similar cells used mainly for growth, repair and replacement, while meiosis produces genetically varied reproductive cells with half the usual chromosome number.
Science
Q355.
Why is DNA important in living organisms?
Answer:
DNA contains genetic information that provides instructions for making proteins and contributes to inherited characteristics.
Science
Q356.
What is the difference between a gene and a chromosome?
Answer:
A gene is a section of DNA containing information related to a characteristic or biological function, while a chromosome is a long DNA molecule associated with proteins and containing many genes.
Science
Q357.
Why does increasing the concentration of reactants often increase reaction rate?
Answer:
A higher concentration means more reacting particles are present in a given volume, increasing the frequency of collisions and therefore usually increasing the reaction rate.
Science
Q358.
What is activation energy?
Answer:
Activation energy is the minimum amount of energy that reacting particles must have for a successful chemical reaction to occur.
Science
Q359.
How does a catalyst affect a chemical reaction?
Answer:
A catalyst provides an alternative reaction pathway with a lower activation energy, increasing the reaction rate without being permanently used up.
Science
Q360.
Why does increasing the thickness of insulation reduce heat transfer?
Answer:
A thicker layer of insulation increases the distance through which thermal energy must be transferred and reduces the rate of energy transfer.
Physics
Q361.
What is meant by scalar quantity?
Answer:
A scalar quantity has magnitude only and no direction.
Physics
Q362.
What is meant by vector quantity?
Answer:
A vector quantity has both magnitude and direction.
Physics
Q363.
What is distance?
Answer:
Distance is the total length of the path travelled by an object.
Physics
Q364.
What is displacement?
Answer:
Displacement is the distance travelled in a particular direction from the starting point.
Physics
Q365.
What is speed?
Answer:
Speed is the distance travelled per unit time.
Physics
Q366.
What is the SI unit of speed?
Answer:
The SI unit of speed is metre per second (m/s).
Physics
Q367.
What is velocity?
Answer:
Velocity is the rate of change of displacement with time.
Physics
Q368.
What is acceleration?
Answer:
Acceleration is the rate of change of velocity with time.
Physics
Q369.
What is the SI unit of acceleration?
Answer:
The SI unit of acceleration is metre per second squared (m/s²).
Physics
Q370.
What is uniform motion?
Answer:
Uniform motion occurs when an object travels equal distances in equal intervals of time.
Physics
Q371.
What is non-uniform motion?
Answer:
Non-uniform motion occurs when an object travels unequal distances in equal intervals of time.
Physics
Q372.
What is Newton's first law of motion?
Answer:
An object remains at rest or in uniform motion unless acted upon by an external resultant force.
Physics
Q373.
What is Newton's second law of motion?
Answer:
The acceleration of an object is proportional to the resultant force and inversely proportional to its mass, giving F = ma.
Physics
Q374.
What is Newton's third law of motion?
Answer:
When two objects interact, they exert equal and opposite forces on each other.
Physics
Q375.
What is force?
Answer:
Force is an interaction that can change an object's motion, direction or shape.
Physics
Q376.
What is the SI unit of force?
Answer:
The SI unit of force is the newton (N).
Physics
Q377.
What is mass?
Answer:
Mass is the amount of matter in an object and is also a measure of its inertia.
Physics
Q378.
What is weight?
Answer:
Weight is the gravitational force acting on an object.
Physics
Q379.
What is the equation for weight?
Answer:
Weight is given by W = mg, where m is mass and g is gravitational field strength.
Physics
Q380.
What is gravitational field strength?
Answer:
Gravitational field strength is the force acting per unit mass at a point in a gravitational field.
Physics
Q381.
What is momentum?
Answer:
Momentum is the product of an object's mass and velocity.
Physics
Q382.
What is the equation for momentum?
Answer:
Momentum is given by p = mv.
Physics
Q383.
What is the principle of conservation of momentum?
Answer:
In a closed system, total momentum remains constant provided no external resultant force acts.
Physics
Q384.
What is work done?
Answer:
Work is done when a force causes an object to move through a distance in the direction of the force.
Physics
Q385.
What is the equation for work done?
Answer:
Work done is W = Fs when the force and displacement are in the same direction.
Physics
Q386.
What is the SI unit of work?
Answer:
The SI unit of work is the joule (J).
Physics
Q387.
What is energy?
Answer:
Energy is the capacity to do work.
Physics
Q388.
What is kinetic energy?
Answer:
Kinetic energy is the energy possessed by an object because of its motion.
Physics
Q389.
What is the equation for kinetic energy?
Answer:
Kinetic energy is KE = ½mv².
Physics
Q390.
What is gravitational potential energy?
Answer:
It is energy stored by an object because of its position in a gravitational field.
Physics
Q391.
What is power?
Answer:
Power is the rate at which energy is transferred or work is done.
Physics
Q392.
What is the equation for power?
Answer:
Power is P = E/t or P = W/t.
Physics
Q393.
What is the SI unit of power?
Answer:
The SI unit of power is the watt (W).
Physics
Q394.
What is energy conservation?
Answer:
Energy cannot be created or destroyed; it can only be transferred between stores or transformed from one form to another.
Physics
Q395.
What is efficiency?
Answer:
Efficiency is the ratio of useful energy transferred to total energy supplied.
Physics
Q396.
What is a renewable energy resource?
Answer:
A renewable energy resource is naturally replenished and can be used repeatedly.
Physics
Q397.
Give an example of a renewable energy resource.
Answer:
Solar energy is an example of a renewable energy resource.
Physics
Q398.
What is a non-renewable energy resource?
Answer:
A non-renewable energy resource is finite and cannot be replenished quickly enough for continued human use.
Physics
Q399.
What is power generated by a hydroelectric system?
Answer:
A hydroelectric system converts the gravitational potential energy of water into electrical energy.
Physics
Q400.
What is a wave?
Answer:
A wave is a transfer of energy from one place to another without an overall transfer of matter.
Physics
Q401.
What is wavelength?
Answer:
Wavelength is the distance between corresponding points on consecutive waves, such as crest to crest.
Physics
Q402.
What is frequency?
Answer:
Frequency is the number of complete waves passing a point each second.
Physics
Q403.
What is the SI unit of frequency?
Answer:
The SI unit of frequency is the hertz (Hz).
Physics
Q404.
What is amplitude?
Answer:
Amplitude is the maximum displacement of a point on a wave from its equilibrium position.
Physics
Q405.
What is the wave equation?
Answer:
Wave speed is given by v = fλ, where f is frequency and λ is wavelength.
Physics
Q406.
What is a transverse wave?
Answer:
In a transverse wave, particles vibrate perpendicular to the direction of energy transfer.
Physics
Q407.
What is a longitudinal wave?
Answer:
In a longitudinal wave, particles vibrate parallel to the direction of energy transfer.
Physics
Q408.
What type of wave is sound?
Answer:
Sound is a longitudinal mechanical wave.
Physics
Q409.
Can sound travel through a vacuum?
Answer:
No, sound needs a medium because it is a mechanical wave.
Physics
Q410.
What determines the pitch of a sound?
Answer:
The frequency of the sound wave determines its pitch.
Physics
Q411.
What determines the loudness of a sound?
Answer:
The amplitude of the sound wave affects its loudness.
Physics
Q412.
What is an electromagnetic wave?
Answer:
An electromagnetic wave is a transverse wave consisting of oscillating electric and magnetic fields.
Physics
Q413.
Can electromagnetic waves travel through a vacuum?
Answer:
Yes, electromagnetic waves can travel through a vacuum.
Physics
Q414.
What is reflection?
Answer:
Reflection is the change in direction of a wave when it bounces from a surface.
Physics
Q415.
What is refraction?
Answer:
Refraction is the change in direction and speed of a wave when it enters a different medium.
Physics
Q416.
What is diffraction?
Answer:
Diffraction is the spreading of waves as they pass through a gap or around an obstacle.
Physics
Q417.
What is the law of reflection?
Answer:
The angle of incidence equals the angle of reflection.
Physics
Q418.
What is a normal in reflection?
Answer:
The normal is a line drawn perpendicular to the reflecting surface at the point of incidence.
Physics
Q419.
What is a lens?
Answer:
A lens is a transparent optical device that refracts light to form images.
Physics
Q420.
What is a convex lens?
Answer:
A convex lens is thicker in the middle and can converge parallel rays of light.
Physics
Q421.
What is a concave lens?
Answer:
A concave lens is thinner in the middle and causes parallel rays of light to diverge.
Physics
Q422.
What is the electromagnetic spectrum?
Answer:
The electromagnetic spectrum is the complete range of electromagnetic radiation arranged by frequency or wavelength.
Physics
Q423.
Which electromagnetic wave has the highest frequency?
Answer:
Gamma radiation has the highest frequency in the electromagnetic spectrum.
Physics
Q424.
Which electromagnetic wave has the longest wavelength?
Answer:
Radio waves have the longest wavelengths.
Physics
Q425.
What is infrared radiation?
Answer:
Infrared is electromagnetic radiation with a longer wavelength than visible light and is strongly associated with thermal radiation.
Physics
Q426.
What is ultraviolet radiation?
Answer:
Ultraviolet radiation has a shorter wavelength than visible violet light and can cause skin damage with excessive exposure.
Physics
Q427.
What is electric current?
Answer:
Electric current is the rate of flow of electric charge.
Physics
Q428.
What is the SI unit of current?
Answer:
The SI unit of current is the ampere (A).
Physics
Q429.
What is potential difference?
Answer:
Potential difference is the energy transferred per unit charge between two points in a circuit.
Physics
Q430.
What is the SI unit of potential difference?
Answer:
The SI unit of potential difference is the volt (V).
Physics
Q431.
What is resistance?
Answer:
Resistance is the opposition to the flow of electric current.
Physics
Q432.
What is the SI unit of resistance?
Answer:
The SI unit of resistance is the ohm (Ω).
Physics
Q433.
What is Ohm's law?
Answer:
For a conductor at constant temperature, the current is directly proportional to the potential difference across it, giving V = IR.
Physics
Q434.
What happens to total resistance when resistors are connected in series?
Answer:
The total resistance is the sum of the individual resistances.
Physics
Q435.
What happens to current in a series circuit?
Answer:
The same current flows through every component in a series circuit.
Physics
Q436.
What happens to potential difference in a series circuit?
Answer:
The supply potential difference is shared between the components.
Physics
Q437.
What happens to current in a parallel circuit?
Answer:
The current splits between the different branches of the circuit.
Physics
Q438.
What happens to potential difference across parallel branches?
Answer:
The potential difference is the same across each parallel branch.
Physics
Q439.
What is electrical power?
Answer:
Electrical power is the rate at which electrical energy is transferred.
Physics
Q440.
What is the equation for electrical power?
Answer:
Electrical power can be calculated using P = VI.
Physics
Q441.
What is electrical energy?
Answer:
Electrical energy is the energy transferred by an electrical device.
Physics
Q442.
What is a fuse?
Answer:
A fuse is a safety device containing a thin wire that melts when excessive current flows.
Physics
Q443.
What is an earth wire?
Answer:
The earth wire provides a low-resistance path to ground if a fault makes a metal case live.
Physics
Q444.
What is static electricity?
Answer:
Static electricity is an imbalance of electric charge that remains on an object's surface.
Physics
Q445.
How are objects charged by friction?
Answer:
Electrons are transferred between materials when they are rubbed together, leaving the objects with opposite charges.
Physics
Q446.
What happens between two like electric charges?
Answer:
Like charges repel each other.
Physics
Q447.
What happens between two unlike electric charges?
Answer:
Unlike charges attract each other.
Physics
Q448.
What is a magnetic field?
Answer:
A magnetic field is a region where magnetic materials or moving charges experience magnetic forces.
Physics
Q449.
What is an electromagnet?
Answer:
An electromagnet is a temporary magnet produced by passing current through a coil of wire.
Physics
Q450.
How can the strength of an electromagnet be increased?
Answer:
Its strength can be increased by increasing the current, increasing the number of coil turns or using a suitable iron core.
Physics
Q451.
What is electromagnetic induction?
Answer:
Electromagnetic induction is the production of a potential difference when the magnetic field through a conductor changes.
Physics
Q452.
What is a generator?
Answer:
A generator converts mechanical energy into electrical energy using electromagnetic induction.
Physics
Q453.
What is a transformer?
Answer:
A transformer changes the potential difference of an alternating current supply using electromagnetic induction.
Physics
Q454.
What is a step-up transformer?
Answer:
A step-up transformer increases the potential difference of an AC supply.
Physics
Q455.
What is a step-down transformer?
Answer:
A step-down transformer decreases the potential difference of an AC supply.
Physics
Q456.
What is the purpose of the National Grid?
Answer:
The National Grid transfers electrical power from power stations to consumers across the country.
Physics
Q457.
Why is electricity transmitted at high potential difference?
Answer:
High potential difference allows the same power to be transmitted with lower current, reducing energy losses in the cables.
Physics
Q458.
What is density?
Answer:
Density is mass per unit volume.
Physics
Q459.
What is the equation for density?
Answer:
Density is given by ρ = m/V.
Physics
Q460.
What is pressure?
Answer:
Pressure is the force acting normally per unit area.
Physics
Q461.
What is the equation for pressure?
Answer:
Pressure is given by p = F/A.
Physics
Q462.
What is the SI unit of pressure?
Answer:
The SI unit of pressure is the pascal (Pa).
Physics
Q463.
What happens to pressure in a liquid as depth increases?
Answer:
Pressure increases as depth increases because there is a greater weight of liquid above.
Physics
Q464.
What is upthrust?
Answer:
Upthrust is the upward force exerted by a fluid on an immersed object.
Physics
Q465.
What is Hooke's law?
Answer:
For an elastic object, extension is proportional to force up to the limit of proportionality.
Physics
Q466.
What is elastic deformation?
Answer:
Elastic deformation is a temporary change in shape where the object returns to its original shape when the force is removed.
Physics
Q467.
What is plastic deformation?
Answer:
Plastic deformation is a permanent change in shape that remains after the force is removed.
Physics
Q468.
What is thermal energy?
Answer:
Thermal energy is energy stored in a substance because of the motion and arrangement of its particles.
Physics
Q469.
What is specific heat capacity?
Answer:
Specific heat capacity is the energy required to raise the temperature of 1 kg of a substance by 1°C.
Physics
Q470.
What is specific latent heat?
Answer:
Specific latent heat is the energy required to change the state of 1 kg of a substance without changing its temperature.
Physics
Q471.
What is conduction?
Answer:
Conduction is the transfer of thermal energy through a material without the material as a whole moving.
Physics
Q472.
What is convection?
Answer:
Convection is the transfer of thermal energy through the movement of a fluid.
Physics
Q473.
What is infrared radiation in heat transfer?
Answer:
Infrared radiation transfers thermal energy by electromagnetic waves and does not require a medium.
Physics
Q474.
What is nuclear fission?
Answer:
Nuclear fission is the splitting of a large unstable nucleus into smaller nuclei, releasing energy and usually neutrons.
Physics
Q475.
What is nuclear fusion?
Answer:
Nuclear fusion is the joining of light nuclei to form a heavier nucleus, releasing energy.
Physics
Q476.
What is radioactive decay?
Answer:
Radioactive decay is the random process in which an unstable nucleus emits radiation and changes into a more stable state.
Physics
Q477.
What is half-life?
Answer:
Half-life is the time taken for the number of unstable nuclei in a radioactive sample to halve.
Geography
Q478.
Why do tropical rainforests have high levels of biodiversity?
Answer:
Warm temperatures, high rainfall and year-round growing conditions provide abundant energy and resources, supporting many specialised species and complex ecosystems.
Geography
Q479.
How can deforestation affect the carbon cycle?
Answer:
Deforestation reduces the number of trees available to absorb carbon dioxide through photosynthesis and can release stored carbon when vegetation is burned or decomposes.
Geography
Q480.
Why can flooding become more severe in urban areas?
Answer:
Buildings, roads and other impermeable surfaces reduce infiltration and increase surface runoff, which can cause water to reach drainage systems and rivers more quickly.
Geography
Q481.
What is a drainage basin?
Answer:
A drainage basin is the area of land drained by a river and its tributaries.
Geography
Q482.
What is the difference between mitigation and adaptation to climate change?
Answer:
Mitigation aims to reduce the causes of climate change, such as greenhouse gas emissions, while adaptation aims to reduce the harm caused by its effects.
Geography
Q483.
Why can development indicators provide an incomplete picture of a country's development?
Answer:
A single indicator may hide differences within a country. Using several measures together can provide a more complete picture of economic, social and environmental conditions.
History
Q484.
What is historical causation?
Answer:
Historical causation is the analysis of the different factors that contributed to an event or development and the relative importance of those factors.
History
Q485.
What is historical continuity and change?
Answer:
Continuity refers to aspects of society that remain relatively stable over time, while change refers to developments or transformations that occur.
History
Q486.
Why should historians consider the purpose of a historical source?
Answer:
The purpose can influence what information the creator included, omitted or emphasised, helping historians assess the source's reliability and limitations.
History
Q487.
What is corroboration in history?
Answer:
Corroboration is the process of comparing different pieces of evidence to see whether they support, contradict or qualify one another.
History
Q488.
Why can a source be useful even if it is biased?
Answer:
A biased source can still reveal valuable information about the attitudes, beliefs, intentions and perspectives of the person or organisation that produced it.
Computing
Q489.
What is computational complexity?
Answer:
Computational complexity describes how the resources required by an algorithm, such as time or memory, change as the size of the input increases.
Computing
Q490.
What is a database primary key?
Answer:
A primary key is a field or combination of fields that uniquely identifies each record in a database table.
Computing
Q491.
What is SQL used for?
Answer:
SQL, or Structured Query Language, is used to create, retrieve, update and manage data in relational databases.
Computing
Q492.
What is authentication?
Answer:
Authentication is the process of verifying the identity of a user or system.
Computing
Q493.
What is the difference between authentication and authorisation?
Answer:
Authentication verifies who a user is, while authorisation determines what that authenticated user is allowed to access or do.
Computing
Q494.
What is a phishing attack?
Answer:
Phishing is a social engineering attack in which an attacker attempts to trick people into revealing information or performing an unsafe action, often through a deceptive message or website.
Art and Design
Q495.
What is conceptual art?
Answer:
Conceptual art places the idea or concept behind an artwork at the centre of the work, sometimes making the idea more important than the physical object.
Art and Design
Q496.
How can an artist communicate social or political ideas?
Answer:
An artist can use symbolism, imagery, composition, materials, scale, colour and visual contrast to communicate ideas about society, politics or human experience.
Art and Design
Q497.
Why is critical evaluation important in art and design?
Answer:
Critical evaluation helps artists analyse their choices, identify strengths and weaknesses and make informed improvements to their work.
Physical Education
Q498.
What is progressive overload?
Answer:
Progressive overload is the gradual increase of training demands placed on the body so that it adapts and becomes fitter or stronger.
Physical Education
Q499.
What is the principle of reversibility?
Answer:
Reversibility means that fitness adaptations can decline when training is reduced or stopped for a significant period.
Physical Education
Q500.
Why is recovery important after intense exercise?
Answer:
Recovery allows the body to repair tissues, restore energy stores and adapt to training. Adequate recovery can also help reduce the risk of excessive fatigue and injury.
Music
Q501.
What is polyphony?
Answer:
Polyphony is a musical texture in which two or more independent melodic lines are performed at the same time.
Music
Q502.
What is musical texture?
Answer:
Musical texture describes how different musical parts and layers are combined within a piece.
Music
Q503.
How can a composer create musical tension?
Answer:
A composer can create tension through dissonance, unresolved harmony, rhythmic instability, increasing volume, rising pitch or changes in texture.
Citizenship
Q504.
What is the principle of parliamentary accountability?
Answer:
Parliamentary accountability means that the government is expected to explain, justify and defend its actions and decisions to Parliament.
Citizenship
Q505.
Why are checks and balances important in democratic government?
Answer:
Checks and balances help prevent the excessive concentration of power by allowing different institutions or processes to scrutinise and constrain decision-making.
Citizenship
Q506.
What is civil society?
Answer:
Civil society consists of voluntary organisations, community groups, charities, associations and other groups that operate independently from the state and contribute to public life.
Citizenship
Q507.
Why is an independent judiciary important?
Answer:
An independent judiciary can make legal decisions without improper political influence and helps uphold the rule of law and legal rights.
Citizenship
Q508.
How can citizens participate in democracy apart from voting?
Answer:
Citizens can participate by contacting representatives, joining organisations, signing petitions, attending public meetings, campaigning, volunteering and engaging in informed public debate.