▶️ Answer/Explanation
Excretion is defined as the removal of toxic materials, waste products of metabolism, and substances in excess of requirements from an organism.
Nutrition is taking in food, respiration is releasing energy from nutrients, and secretion is the release of useful substances (e.g. enzymes) made by a cell.
Only excretion matches the description of removing toxic waste.
✅ Answer: (A)
Nutrition is taking in food, respiration is releasing energy from nutrients, and secretion is the release of useful substances (e.g. enzymes) made by a cell.
Only excretion matches the description of removing toxic waste.
✅ Answer: (A)
▶️ Answer/Explanation
Cells specialised for diffusion (such as root hair cells and alveolar cells) are flattened, elongated, or have projections that increase their surface area relative to volume.
Cells 1 and 4 in the diagram show this type of shape, unlike the more compact/rounded cells 2 and 3.
A larger surface area speeds up the rate of diffusion of substances into and out of the cell.
✅ Answer: (B)
Cells 1 and 4 in the diagram show this type of shape, unlike the more compact/rounded cells 2 and 3.
A larger surface area speeds up the rate of diffusion of substances into and out of the cell.
✅ Answer: (B)
▶️ Answer/Explanation
An egg contains protein and fat but no starch and no reducing sugar, so Benedict’s test stays blue (no sugar) and the iodine test stays yellow-brown/orange (no starch).
The biuret test turns purple because protein is present, and the ethanol emulsion test produces a white emulsion because fat is present.
Only row A shows this exact combination of results.
✅ Answer: (A)
The biuret test turns purple because protein is present, and the ethanol emulsion test produces a white emulsion because fat is present.
Only row A shows this exact combination of results.
✅ Answer: (A)
▶️ Answer/Explanation
Lowering the temperature below the optimum reduces the kinetic energy of enzyme and substrate molecules, so collisions happen less frequently.
This means the formation of product decreases, since fewer successful enzyme-substrate collisions occur.
The active site’s shape is unaffected by cooling (only high temperatures denature it), so it shows no change.
✅ Answer: (A)
This means the formation of product decreases, since fewer successful enzyme-substrate collisions occur.
The active site’s shape is unaffected by cooling (only high temperatures denature it), so it shows no change.
✅ Answer: (A)
▶️ Answer/Explanation
Glucose molecules made in photosynthesis can be joined together to form starch, which is the plant’s main storage carbohydrate.
X represents the addition of a nitrogen-containing substance (such as nitrate ions) needed to convert glucose into amino acids, so X is not magnesium or iron.
Y, formed by joining many glucose molecules, is therefore starch and not an oil molecule.
✅ Answer: (C)
X represents the addition of a nitrogen-containing substance (such as nitrate ions) needed to convert glucose into amino acids, so X is not magnesium or iron.
Y, formed by joining many glucose molecules, is therefore starch and not an oil molecule.
✅ Answer: (C)
▶️ Answer/Explanation
Kwashiorkor is a protein deficiency disease that classically causes a swollen abdomen due to fluid retention, skin rashes/patches, and muscle wasting.
Marasmus, by contrast, causes overall severe wasting without the swollen belly, and iron deficiency or scurvy produce different symptoms (anaemia, or bleeding gums respectively).
The combination of symptoms described matches kwashiorkor specifically.
✅ Answer: (B)
Marasmus, by contrast, causes overall severe wasting without the swollen belly, and iron deficiency or scurvy produce different symptoms (anaemia, or bleeding gums respectively).
The combination of symptoms described matches kwashiorkor specifically.
✅ Answer: (B)
▶️ Answer/Explanation
Water evaporates from the moist surfaces of mesophyll cells inside the leaf, forming water vapour in the air spaces.
This vapour then diffuses out through the stomata (guard cell pores), but it is the mesophyll cells, not the guard cells themselves, where evaporation occurs.
Epidermis and root hair cells are not the sites of this evaporation step in transpiration.
✅ Answer: (C)
This vapour then diffuses out through the stomata (guard cell pores), but it is the mesophyll cells, not the guard cells themselves, where evaporation occurs.
Epidermis and root hair cells are not the sites of this evaporation step in transpiration.
✅ Answer: (C)
▶️ Answer/Explanation
Photosynthesis requires a continuous input of light energy to build glucose from carbon dioxide and water, so it is an endothermic process.
Respiration breaks down glucose and releases energy overall for the cell to use, making it exothermic.
Only row C shows respiration as exothermic and photosynthesis as endothermic.
✅ Answer: (C)
Respiration breaks down glucose and releases energy overall for the cell to use, making it exothermic.
Only row C shows respiration as exothermic and photosynthesis as endothermic.
✅ Answer: (C)
▶️ Answer/Explanation
Adrenaline is a chemical messenger secreted directly into the blood by the adrenal glands, which is the definition of a hormone.
It is not an enzyme (which catalyses reactions), a mineral salt, or a vitamin.
Adrenaline travels in the blood to target organs, increasing heart rate and preparing the body for action.
✅ Answer: (B)
It is not an enzyme (which catalyses reactions), a mineral salt, or a vitamin.
Adrenaline travels in the blood to target organs, increasing heart rate and preparing the body for action.
✅ Answer: (B)
▶️ Answer/Explanation
Pollination is defined as the transfer of pollen grains from the anther (male part) to the stigma (female part) of a flower.
In the diagram, this corresponds to the labelled structure representing the stigma, which is the receptive surface at the top of the carpel.
Reaching any other structure (ovary, ovule, ovary wall) would not count as pollination itself.
✅ Answer: (B)
In the diagram, this corresponds to the labelled structure representing the stigma, which is the receptive surface at the top of the carpel.
Reaching any other structure (ovary, ovule, ovary wall) would not count as pollination itself.
✅ Answer: (B)
▶️ Answer/Explanation
Selective breeding is a human-controlled process in which breeders choose parents with desirable characteristics, so it is called artificial selection, not natural selection.
Natural selection instead happens without human choice, driven by survival and reproduction in the wild.
Changing “natural” to “artificial” is the only edit that makes the statement scientifically accurate.
✅ Answer: (D)
Natural selection instead happens without human choice, driven by survival and reproduction in the wild.
Changing “natural” to “artificial” is the only edit that makes the statement scientifically accurate.
✅ Answer: (D)
▶️ Answer/Explanation
Kelp is the producer, so organisms that eat kelp directly (like the sea urchin) are primary consumers, and organisms that eat those primary consumers are secondary consumers.
Tracing the web, the sea otter and large fish each eat primary consumers, making them secondary consumers, while the sea otter, killer whale and seal all feed at a level higher again in different branches, making them tertiary consumers too.
Only the combination in row C, “sea otter, large fish” as secondary and “sea otter, killer whale, seal” as tertiary, correctly reflects an organism occupying more than one trophic level in a web.
✅ Answer: (C)
Tracing the web, the sea otter and large fish each eat primary consumers, making them secondary consumers, while the sea otter, killer whale and seal all feed at a level higher again in different branches, making them tertiary consumers too.
Only the combination in row C, “sea otter, large fish” as secondary and “sea otter, killer whale, seal” as tertiary, correctly reflects an organism occupying more than one trophic level in a web.
✅ Answer: (C)
▶️ Answer/Explanation
Excess nutrients cause algae/producers to grow rapidly (an increase, not a decrease), and when they die, decomposers respire aerobically to break them down (also increasing).
This heavy aerobic respiration by decomposers uses up dissolved oxygen faster than it can be replaced.
As a result, dissolved oxygen in the water falls, which is the quantity that decreases.
✅ Answer: (C)
This heavy aerobic respiration by decomposers uses up dissolved oxygen faster than it can be replaced.
As a result, dissolved oxygen in the water falls, which is the quantity that decreases.
✅ Answer: (C)
▶️ Answer/Explanation
Filtration first separates the insoluble solid sulfur from the sodium chloride solution, since sulfur cannot pass through the filter paper.
The filtrate, a sodium chloride solution, is then heated to evaporate water until saturated, and cooled to allow crystals of sodium chloride to form — this is crystallisation.
Distillation and chromatography are not needed here, since the goal is to recover a dissolved solid, not to separate a liquid mixture or coloured substances.
✅ Answer: (D)
The filtrate, a sodium chloride solution, is then heated to evaporate water until saturated, and cooled to allow crystals of sodium chloride to form — this is crystallisation.
Distillation and chromatography are not needed here, since the goal is to recover a dissolved solid, not to separate a liquid mixture or coloured substances.
✅ Answer: (D)
▶️ Answer/Explanation
The atomic number, \( 49 \), gives the number of protons, which for a neutral atom also equals the number of electrons.
The number of neutrons is found using \( \text{neutrons} = \text{nucleon number} – \text{atomic number} = 115 – 49 = 66 \).
So this atom has 49 protons, 66 neutrons and 49 electrons.
✅ Answer: (A)
The number of neutrons is found using \( \text{neutrons} = \text{nucleon number} – \text{atomic number} = 115 – 49 = 66 \).
So this atom has 49 protons, 66 neutrons and 49 electrons.
✅ Answer: (A)
▶️ Answer/Explanation
A correctly balanced equation must use molecular oxygen, \( O_2 \), not free oxygen atoms, which rules out options C and D.
Balancing carbon gives 5 carbon atoms split between \( CO_2 \) and \( CO \), and balancing hydrogen gives \( 6H_2O \); checking option A: \( 3CO_2 + 2CO + 6H_2O \) uses \( (3\times2)+2+6 = 14 \) oxygen atoms, matching \( 7O_2 \).
Option B does not balance oxygen atoms correctly, so it is incorrect.
✅ Answer: (A)
Balancing carbon gives 5 carbon atoms split between \( CO_2 \) and \( CO \), and balancing hydrogen gives \( 6H_2O \); checking option A: \( 3CO_2 + 2CO + 6H_2O \) uses \( (3\times2)+2+6 = 14 \) oxygen atoms, matching \( 7O_2 \).
Option B does not balance oxygen atoms correctly, so it is incorrect.
✅ Answer: (A)
▶️ Answer/Explanation
Aqueous copper(II) sulfate is indeed used as the electrolyte, so statement 1 is correct.
The anode in copper refining is impure copper itself, not an inert material, so statement 2 is wrong; and pure copper is deposited at the cathode, not the anode, so statement 4 is wrong.
At the cathode, \( Cu^{2+} + 2e^- \rightarrow Cu \), which is a gain of electrons, confirming statement 3 (reduction at the cathode) is correct.
✅ Answer: (B)
The anode in copper refining is impure copper itself, not an inert material, so statement 2 is wrong; and pure copper is deposited at the cathode, not the anode, so statement 4 is wrong.
At the cathode, \( Cu^{2+} + 2e^- \rightarrow Cu \), which is a gain of electrons, confirming statement 3 (reduction at the cathode) is correct.
✅ Answer: (B)
▶️ Answer/Explanation
Endothermic reactions absorb energy from their surroundings, so the surroundings lose thermal energy and the temperature decreases.
Exothermic reactions release energy, but the size of the temperature rise depends on the amounts and concentrations reacting, so it cannot always be described as “large” or “small”.
Only the statement about endothermic reactions causing a temperature decrease is universally true.
✅ Answer: (A)
Exothermic reactions release energy, but the size of the temperature rise depends on the amounts and concentrations reacting, so it cannot always be described as “large” or “small”.
Only the statement about endothermic reactions causing a temperature decrease is universally true.
✅ Answer: (A)
▶️ Answer/Explanation
Increasing temperature gives particles more kinetic energy, so they move faster and collide with each other more often, increasing the frequency of collisions.
The extra kinetic energy also means each collision happens with greater force, increasing the energy of the collisions.
Both frequency and energy of collisions increase with temperature, which is why reaction rate rises as temperature rises.
✅ Answer: (D)
The extra kinetic energy also means each collision happens with greater force, increasing the energy of the collisions.
Both frequency and energy of collisions increase with temperature, which is why reaction rate rises as temperature rises.
✅ Answer: (D)
▶️ Answer/Explanation
Excess copper(II) oxide is used to ensure all the acid reacts, not specifically for “a high yield” phrasing — the true purpose is to guarantee no leftover acid contaminates the salt, so statement 1 is not the intended reason and is considered incorrect here.
After filtering, heating the solution does evaporate some water until saturation point is reached, making statement 2 correct.
Cooling a saturated solution lowers its solubility limit, so crystals of copper(II) sulfate begin forming as it cools, making statement 3 correct; statement 4 is wrong since crystallisation relies on slow cooling, not rapid evaporation after cooling.
✅ Answer: (C)
After filtering, heating the solution does evaporate some water until saturation point is reached, making statement 2 correct.
Cooling a saturated solution lowers its solubility limit, so crystals of copper(II) sulfate begin forming as it cools, making statement 3 correct; statement 4 is wrong since crystallisation relies on slow cooling, not rapid evaporation after cooling.
✅ Answer: (C)
▶️ Answer/Explanation
Transition elements are well known for forming brightly coloured compounds, such as blue copper(II) sulfate or purple potassium manganate(VII), not colourless ones.
They do have high densities, high melting points, and many act as catalysts (e.g. iron, nickel, platinum), so statements A, C and D are all correct.
The claim that they “always” form colourless compounds is the incorrect statement.
✅ Answer: (B)
They do have high densities, high melting points, and many act as catalysts (e.g. iron, nickel, platinum), so statements A, C and D are all correct.
The claim that they “always” form colourless compounds is the incorrect statement.
✅ Answer: (B)
▶️ Answer/Explanation
Catalytic converters are designed to remove pollutant gases such as nitrogen oxides from vehicle exhaust before they reach the atmosphere.
They achieve this by converting harmful nitrogen monoxide back into harmless nitrogen and oxygen gases, as shown by \( 2NO \rightarrow N_2 + O_2 \).
The other equations describe nitrogen oxide/ammonia/sulfur oxide formation reactions, which are not what happens inside a catalytic converter.
✅ Answer: (B)
They achieve this by converting harmful nitrogen monoxide back into harmless nitrogen and oxygen gases, as shown by \( 2NO \rightarrow N_2 + O_2 \).
The other equations describe nitrogen oxide/ammonia/sulfur oxide formation reactions, which are not what happens inside a catalytic converter.
✅ Answer: (B)
▶️ Answer/Explanation
The Haber process uses an iron catalyst, not vanadium(V) oxide — vanadium(V) oxide is instead the catalyst used in the separate Contact process for making sulfuric acid.
Nitrogen for the process is correctly obtained from the air, and the typical operating conditions are around 200 atmospheres pressure and \( 450\ ^{\circ}C \), so statements B, C and D are accurate.
The catalyst described in statement A is therefore the incorrect one.
✅ Answer: (A)
Nitrogen for the process is correctly obtained from the air, and the typical operating conditions are around 200 atmospheres pressure and \( 450\ ^{\circ}C \), so statements B, C and D are accurate.
The catalyst described in statement A is therefore the incorrect one.
✅ Answer: (A)
▶️ Answer/Explanation
The Contact process proceeds through several stages: sulfur burns to form \( SO_2 \), which is then catalytically oxidised to \( SO_3 \), and \( SO_3 \) is subsequently reacted further to eventually produce \( H_2SO_4 \).
\( SO_3 \) is therefore a product of the oxidation step but also a reactant in the next stage where it is converted onward towards sulfuric acid.
\( H_2O \), \( O_2 \) and \( S \) each appear only as reactants (or are not part of these particular equations) rather than as both a product and a reactant.
✅ Answer: (D)
\( SO_3 \) is therefore a product of the oxidation step but also a reactant in the next stage where it is converted onward towards sulfuric acid.
\( H_2O \), \( O_2 \) and \( S \) each appear only as reactants (or are not part of these particular equations) rather than as both a product and a reactant.
✅ Answer: (D)
▶️ Answer/Explanation
Limestone is chemically known as calcium carbonate, \( CaCO_3 \), not calcium oxide.
On heating, it undergoes thermal decomposition according to \( CaCO_3 \rightarrow CaO + CO_2 \), producing both calcium oxide and carbon dioxide as products.
Only the row naming limestone as calcium carbonate and listing both products matches this correctly.
✅ Answer: (B)
On heating, it undergoes thermal decomposition according to \( CaCO_3 \rightarrow CaO + CO_2 \), producing both calcium oxide and carbon dioxide as products.
Only the row naming limestone as calcium carbonate and listing both products matches this correctly.
✅ Answer: (B)
▶️ Answer/Explanation
Each petroleum fraction has a defined main use: refinery gas for heating/cooking, gasoline for car fuel, and bitumen for road-making.
Naphtha, however, is the fraction specifically used as a chemical feedstock, providing starting materials for the petrochemical industry (e.g. to make alkenes and polymers).
This makes naphtha the correct answer for a chemical feedstock fraction.
✅ Answer: (C)
Naphtha, however, is the fraction specifically used as a chemical feedstock, providing starting materials for the petrochemical industry (e.g. to make alkenes and polymers).
This makes naphtha the correct answer for a chemical feedstock fraction.
✅ Answer: (C)
▶️ Answer/Explanation
But-2-ene, \( CH_3-CH=CH-CH_3 \), has its double bond between carbons 2 and 3, with a methyl group attached to each of these carbons.
In addition polymerisation, the double bond opens up and the monomers join through single bonds, so the repeat unit must show a methyl group (\( CH_3 \)) branching off each backbone carbon in the chain.
Only the structure that keeps both methyl side-groups on adjacent backbone carbons correctly represents the polymer of but-2-ene.
✅ Answer: (D)
In addition polymerisation, the double bond opens up and the monomers join through single bonds, so the repeat unit must show a methyl group (\( CH_3 \)) branching off each backbone carbon in the chain.
Only the structure that keeps both methyl side-groups on adjacent backbone carbons correctly represents the polymer of but-2-ene.
✅ Answer: (D)
▶️ Answer/Explanation
The distance travelled is equal to the total area under a speed–time graph.
The graph rises from \( 0 \) to \( 0.8 \) km/minute over the first minute, stays constant at \( 0.8 \) km/minute for the next two minutes, then falls back to \( 0 \) over the final minute, giving areas of \( 0.4 + 1.6 + 0.4 \) km.
Adding these together, \( 0.4 + 1.6 + 0.4 = 2.4 \) km.
✅ Answer: (C)
The graph rises from \( 0 \) to \( 0.8 \) km/minute over the first minute, stays constant at \( 0.8 \) km/minute for the next two minutes, then falls back to \( 0 \) over the final minute, giving areas of \( 0.4 + 1.6 + 0.4 \) km.
Adding these together, \( 0.4 + 1.6 + 0.4 = 2.4 \) km.
✅ Answer: (C)
▶️ Answer/Explanation
The base of the box in contact with the ground has an area \( A = 0.50\ m \times 0.40\ m = 0.20\ m^2 \).
Pressure is defined as \( P = \dfrac{F}{A} \), so rearranging gives \( F = P \times A \).
Substituting the values, \( F = 50\ Pa \times 0.20\ m^2 = 10\ N \), which is the weight of the box.
✅ Answer: (B)
Pressure is defined as \( P = \dfrac{F}{A} \), so rearranging gives \( F = P \times A \).
Substituting the values, \( F = 50\ Pa \times 0.20\ m^2 = 10\ N \), which is the weight of the box.
✅ Answer: (B)
▶️ Answer/Explanation
Geothermal energy comes from heat continually generated within the Earth, so it is classed as a renewable energy resource that will not run out on a human timescale.
Nuclear power, in contrast, relies on a finite supply of uranium fuel that is mined and used up, making it a non-renewable resource.
So geothermal power is renewable while nuclear power is not.
✅ Answer: (C)
Nuclear power, in contrast, relies on a finite supply of uranium fuel that is mined and used up, making it a non-renewable resource.
So geothermal power is renewable while nuclear power is not.
✅ Answer: (C)
▶️ Answer/Explanation
Efficiency measures how much of the energy supplied to a device is converted into a useful form, rather than wasted as heat or sound.
It is defined as \( \text{efficiency} = \dfrac{\text{useful energy output}}{\text{total energy input}} \times 100\% \).
The other options either invert the fraction or use “wasted energy” in place of “useful energy output”, which does not match the correct definition.
✅ Answer: (A)
It is defined as \( \text{efficiency} = \dfrac{\text{useful energy output}}{\text{total energy input}} \times 100\% \).
The other options either invert the fraction or use “wasted energy” in place of “useful energy output”, which does not match the correct definition.
✅ Answer: (A)
▶️ Answer/Explanation
Arrow P shows particles becoming more spread out and disordered, going from a closely packed regular arrangement to a widely spaced random one — this is evaporation, a change from liquid to gas.
Arrow Q shows particles becoming more ordered and closely packed, going from a disordered liquid arrangement to a fixed regular one — this is solidification, a change from liquid to solid.
Only the row pairing P with evaporation and Q with solidification matches the diagrams.
✅ Answer: (B)
Arrow Q shows particles becoming more ordered and closely packed, going from a disordered liquid arrangement to a fixed regular one — this is solidification, a change from liquid to solid.
Only the row pairing P with evaporation and Q with solidification matches the diagrams.
✅ Answer: (B)
▶️ Answer/Explanation
The wave equation \( v = f\lambda \) relates speed, frequency and wavelength, so rearranging gives \( \lambda = \dfrac{v}{f} \).
First convert the frequency to hertz: \( 16\ kHz = 16000\ Hz \).
Substituting, \( \lambda = \dfrac{320}{16000} = 0.020\ m \).
✅ Answer: (A)
First convert the frequency to hertz: \( 16\ kHz = 16000\ Hz \).
Substituting, \( \lambda = \dfrac{320}{16000} = 0.020\ m \).
✅ Answer: (A)
▶️ Answer/Explanation
As light travels from the less dense air into the denser glass, it slows down and bends towards the normal at the first surface.
As it then leaves the glass and re-enters air at the second (parallel) surface, it speeds up again and bends away from the normal by the same angle.
This produces an emerging ray that is parallel to, but laterally displaced from, the original incident ray — only one diagram shows this correctly.
✅ Answer: (A)
As it then leaves the glass and re-enters air at the second (parallel) surface, it speeds up again and bends away from the normal by the same angle.
This produces an emerging ray that is parallel to, but laterally displaced from, the original incident ray — only one diagram shows this correctly.
✅ Answer: (A)
▶️ Answer/Explanation
At position P, between \( f \) and \( 2f \), a converging lens forms a real, enlarged image.
When the object moves to position Q, inside the focal length \( f \), the lens can no longer converge the rays to a real point, so a virtual image forms instead.
A virtual image formed by a converging lens with the object inside the focal length is always magnified, so the image remains enlarged throughout.
✅ Answer: (D)
When the object moves to position Q, inside the focal length \( f \), the lens can no longer converge the rays to a real point, so a virtual image forms instead.
A virtual image formed by a converging lens with the object inside the focal length is always magnified, so the image remains enlarged throughout.
✅ Answer: (D)
▶️ Answer/Explanation
An ammeter must be connected in series in the main circuit loop so that the full current flowing through the resistor also flows through it.
A voltmeter must be connected in parallel across the resistor, so it measures the potential difference between its two ends without diverting current from the main circuit.
Only one circuit diagram shows the ammeter in series and the voltmeter in parallel in this way.
✅ Answer: (A)
A voltmeter must be connected in parallel across the resistor, so it measures the potential difference between its two ends without diverting current from the main circuit.
Only one circuit diagram shows the ammeter in series and the voltmeter in parallel in this way.
✅ Answer: (A)
▶️ Answer/Explanation
First find the current using \( I = \dfrac{V}{R} = \dfrac{12}{3.0} = 4.0\ A \).
Electrical power is given by \( P = VI = 12 \times 4.0 = 48\ W \).
Energy transferred is \( E = Pt = 48 \times 10 = 480\ J \).
✅ Answer: (D)
Electrical power is given by \( P = VI = 12 \times 4.0 = 48\ W \).
Energy transferred is \( E = Pt = 48 \times 10 = 480\ J \).
✅ Answer: (D)
▶️ Answer/Explanation
A current-carrying solenoid produces a magnetic field pattern very similar to that of a bar magnet, with field lines emerging from one end (north pole) and curving round to enter the other end (south pole).
Inside the solenoid, the field lines run parallel to the axis and are evenly spaced, showing a strong, uniform field.
Only one diagram correctly shows this bar-magnet-like pattern both inside and outside the coil.
✅ Answer: (D)
Inside the solenoid, the field lines run parallel to the axis and are evenly spaced, showing a strong, uniform field.
Only one diagram correctly shows this bar-magnet-like pattern both inside and outside the coil.
✅ Answer: (D)
▶️ Answer/Explanation
Part X, in contact with the brushes, is the split-ring commutator, not a step-down transformer (which is an entirely different component used to change a.c. voltage).
Its role is to reverse the direction of current flowing through the coil every half turn.
This keeps the turning forces on each side of the coil acting in the same rotational direction, allowing the motor to spin continuously rather than oscillating back and forth.
✅ Answer: (B)
Its role is to reverse the direction of current flowing through the coil every half turn.
This keeps the turning forces on each side of the coil acting in the same rotational direction, allowing the motor to spin continuously rather than oscillating back and forth.
✅ Answer: (B)
▶️ Answer/Explanation
The positively charged \( \alpha \)-particles are attracted towards the negative (upper) plate, while the negatively charged \( \beta \)-particles are attracted towards the positive (lower) plate, so they deflect in opposite directions.
\( \beta \)-particles have a much smaller mass than \( \alpha \)-particles but carry a comparable magnitude of charge, so for the same field they experience a much greater deflection.
This means \( \beta \)-particles bend towards the lower plate and \( \alpha \)-particles towards the upper plate, with \( \beta \)-particles deflected more.
✅ Answer: (D)
\( \beta \)-particles have a much smaller mass than \( \alpha \)-particles but carry a comparable magnitude of charge, so for the same field they experience a much greater deflection.
This means \( \beta \)-particles bend towards the lower plate and \( \alpha \)-particles towards the upper plate, with \( \beta \)-particles deflected more.
✅ Answer: (D)