Questions 1
(a) Topic – 5.c
(b) Topic-5.c
The table shows an incomplete electromagnetic spectrum.
Two parts of the electromagnetic spectrum are missing. The missing parts are labelled A and B.
(a) (i) Name the part labelled A.
(ii) Name the part labelled B.
(b) (i) Give a use of microwaves.
(ii) Give a use of gamma rays.
▶️Answer/Explanation
Ans
(a) (i) infrared;
(ii) ultraviolet;
(b) (i) heating food / eq;
communication;
radar;
(ii) sterilising (equipment or food);
treating cancer;
medical imaging;
medical tracing techniques;
Questions 2
(a) Topic – 2.b
(b) Topic-2.b
(c) Topic-2.b
The photograph shows an electric heater connected to the mains electricity supply.
The circuit the heater is connected to is fitted with a circuit breaker, which breaks the circuit if the current gets too high.
(a) Give an advantage of using a circuit breaker instead of using a fuse.
(b) The voltage of the mains electricity supply is 230V.
(i) State the formula linking power, current and voltage.
(ii) The normal operating current of the heater is 11A. Calculate the input power to the heater for this current. Give your answer in kW.
(c) The circuit breaker has a rating of 16A. Suggest a reason why the heater may switch off before it reaches its normal operating current
▶️Answer/Explanation
Ans
(a) any of:
● idea that circuit breaker can easily be reset;
● idea that circuit breaker turns off circuit more quickly;
(b) (i) power = current × voltage;
(ii) substitution;
evaluation in W;
evaluation in kW;
e.g.
power = 11 × 230
(power =) 2500 (W)
(power =) 2.5 (kW)
(c) any of:
● idea that there are likely to be other appliances on same circuit;
● fuse in heater may be rated at less than 16A;
● idea that heater may have a (thermal) safety cut-out;
● idea that thermostat turns off heater;
Questions 3
(a) Topic – 1.b
(b) Topic-1.b
In 1947, the Railton Mobil Special was the first ground vehicle to achieve a speed of more than 400 miles per hour.
(a) During a test, the vehicle travelled at a speed of 403 miles per hour.
(i) Calculate a speed of 403 miles per hour in metres per second (m/s).
[1 mile = 1600m]
(ii) During the test, the vehicle travelled past two markers. The markers were placed a known distance apart. Describe how these markers could be used to determine the speed of the vehicle.
(b) The diagram shows the vehicle travelling at a constant speed.
One of the horizontal forces acting on the vehicle has been drawn. Complete the diagram by drawing a labelled arrow for the other horizontal force acting on the vehicle.
▶️Answer/Explanation
Ans
(a) (i) × 1600 seen in working OR ÷ 3600 seen in working;
speed = 179 (m/s);
(ii) idea of measuring time taken (to travel between markers);
use of appropriate instrument to measure time;
use of speed = distance / time;
(b) length of arrow equal to given arrow;
arrow drawn horizontally to the left;
arrow labelled “air resistance”;
Questions 4
(a) Topic – 9.c
(b) Topic-9.c
(c) Topic-9.b
This question is about the Sun.
(a) The table shows the different stages in the evolution of stars of different masses. Complete the table by adding ticks (ü) to show which stages of evolution occur in the life cycle of the Sun.
(b) When viewed from Earth, the surface of the Sun is yellow in colour. The surface of another star, Betelgeuse, is red in colour. Explain the difference between the Sun and Betelgeuse, based on the different colours of their surfaces.
(c) The Sun transfers energy to the Earth by radiation.
(i) Give a reason why energy is not transferred from the Sun to the Earth by conduction or convection.
(ii) A satellite orbiting the Earth contains sensitive equipment that can be damaged if it gets too hot. Explain which colour would be most appropriate for the outer surface of the satellite to protect the equipment.
▶️Answer/Explanation
Ans
(a) one mark for each correct tick;;;;
(b) idea of the temperatures being different;
Sun is hotter than Betelgeuse;
(c) (i) idea that there are no particles in space (between Sun and Earth);
(ii) shiny / white / silver;
poor absorber of (IR) radiation;
Questions 5
(a) Topic – 4.b
(b) Topic-4.b
A student needs to determine the density of some small rocks that appear to all be made of the same material.
(a) The student decides to measure the mass and the volume of each rock. Describe a method the student could use to accurately determine the mass and the volume of each rock. You may draw a diagram to help your answer.
(b) The table shows the student’s results for three of the rocks.
(i) State the formula linking density, mass and volume.
(ii) After looking at the data, the student concludes that one of the rocks may be made of a different material from the others. Using the data from the table, justify the student’s conclusion.
▶️Answer/Explanation
Ans
(a) MP1. use balance to measure mass;
MP2. use of measuring cylinder to measure volume;
PLUS
Any three from:
MP3. ensure balance reads zero before placing rock;
MP4. ensure balance is on a level surface;
MP5. ensure rock is dry when measuring its mass
MP6. recording volume before rock added to water
MP7. finding difference in volume of water after rock added
MP8. ensure rock is fully submerged;
MP9. ensure no water is spilt / all water collected by measuring cylinder;
MP10. read measuring cylinder at eye level / on a level surface;
MP11. read to bottom of water meniscus;
(b) (i) density = mass / volume;
(ii) idea that different materials have different densities;
correct evaluation of density for at least one rock;
correct evaluation of density for all rocks;
conclusion from density values that rock A is made from a different material (so student is correct);
Questions 6
(a) Topic – 5.d
(b) Topic-5.d
The diagram shows two rays of green light entering a semicircular glass block.
(a) (i) Measure the angle of incidence and the angle of refraction for ray A as it enters the glass block.
(ii) State the formula linking refractive index, angle of incidence and angle of refraction.
(iii) Calculate the refractive index of the glass.
(b) (i) Complete the path of ray A until it crosses ray B. Label the point where the rays cross with the letter F.
(ii) The refractive index of glass for red light is lower than for green light. Explain what would happen to point F if red light were used instead of green light. You may draw a diagram to help your answer.
▶️Answer/Explanation
Ans
(a) (i) angle of incidence = 40°;
angle of refraction = 23°
(ii) n = sin(i)/sin(r);
(iii) substitution of candidate’s values into formula;
e.g.
n = sin(40)/sin(23)
n = 1.6(5)
(b) (i) single ray emerges and extended to horizontal ray;
ray bends away from normal by eye;
(ii) idea that F moves away from the prism;
idea that red ray bends less than green at either interface;
idea that red ray bends less than green at both interfaces;
Questions 7
(a) Topic – 2.b
(b) Topic-2.c
A student investigates the voltage-current characteristics of an unknown component, X.
(a) The student is given this equipment to investigate component X.
• battery
• variable resistor
• ammeter
• voltmeter
• connecting wires
The diagram shows an incomplete circuit containing the battery and component X. Complete the diagram by drawing a circuit the student could use for their investigation.
(b) The graph shows the results of the investigation.
(i) Draw a line of best fit on the graph.
(ii) Calculate the resistance of component X when the voltage is 4.2V. Give the unit.
(iii) Which of these is equivalent to 4.2V?
A 4.2 coulombs per second (C/s)
B 4.2 seconds per joule (s/J)
C 4.2 joules per second (J/s)
D 4.2 joules per coulomb (J/C)
(iv) The student concludes that component X is a filament lamp. Comment on the student’s conclusion.
▶️Answer/Explanation
Ans
(a) circuit symbols for variable resistor, ammeter and voltmeter drawn correctly;
variable resistor drawn in series with battery and component X;
ammeter drawn in series with component X;
voltmeter drawn in parallel with component X;
(b) (i) straight line of best fit drawn with points distributed equally either side;
(ii) use of voltage = current × resistance;
correct reading of current from graph;
substitution OR rearrangement;
evaluation;
matching unit;
e.g.
V = I × R
current = 2.35 (×10⁻³) (A)
4.2 = 2.35 (×10⁻³) × R OR R = V / I
(resistance =) 1800
ohms / Ω
(iii) D (4.2 joules per coulomb); 1
A is incorrect because this is the unit for current
B is incorrect because this is the reciprocal of the unit for power
C is incorrect because this is the unit for power
(iv) graph for lamp should be a curve;
(because) a lamp does not obey Ohm’s Law/ lamp
does not have I directly proportional to V.
component X is a resistor;
Questions 8
(a) Topic – 8.b
(b) Topic-8.b
(c) Topic-8.b
This question is about radioactive isotopes used for medical imaging.
(a) Iodine-131 is represented by this symbol.
\(^{131}_{53}I\)
(i) How many neutrons are in the nucleus of an atom of iodine-131?
A 53
B 78
C 131
D 184
(ii) Iodine-131 is radioactive and decays with a half-life of 8 days. State what is meant by the term half-life.
(iii) The cross (×) on the graph shows the initial number of atoms in a sample of iodine-131. Draw three more crosses (×) on the graph to show how the number of atoms of iodine-131 in the sample changes during three half-lives.
[iodine-131 half-life = 8 days]
(iv) Use a curve of best fit on the graph to estimate the time taken for the number of atoms in the sample to decrease to 5000.
(b) When iodine-131 decays, it emits beta radiation and gamma radiation. A patient swallows a tablet containing iodine-131. The radiation emitted can be detected outside the body.
(i) State the name of a piece of equipment that can detect the radiation emitted by iodine-131.
(ii) Give a reason why gamma radiation is more likely to be detected outside the body than beta radiation.
(c) Technetium-99m is another radioactive isotope. Iodine-131 and technetium-99m are both used as medical tracers. Medical tracers use radiation detected outside the body to diagnose illnesses. The table gives information about some of the properties of iodine-131 and technetium-99m when they undergo radioactive decay.
Explain why technetium-99m is likely to be safer than iodine-131 when used as a medical tracer.
▶️Answer/Explanation
Ans
(a) (i) B (78);
A is incorrect because this is the number of protons
C is incorrect because this is the number of nucleons
D is incorrect because this is the number of nucleons + protons
(ii) time taken;
and either of for (radio)activity to halve;
for half of the (radioactive) {nuclei / atoms / isotope / mass} to decay;
(iii) one mark for each correct cross drawn
(8, 8000);
(16, 4000);
(24, 2000);
(iv) smooth curve of best fit drawn;
correct reading of time to decrease to 5000;
(b) (i) Geiger(-muller) tube/ GM tube / photographic film / scintillator;
(ii) idea that gamma is more penetrating than beta;
(c) any three from:
MP1. gamma is less ionising than beta;
MP2. beta is more likely to cause cell damage than gamma;
MP3. technetium decays more quickly;
MP4. technetium is in the body for less time/short time;
Questions 9
(a) Topic – 1.b
(b) Topic-1.c
(c) Topic-1.b
A student stretches a rubber band.
(a) The photographs show a rubber band before and after it has been stretched.
(i) State which energy store increases in the rubber band after it has been stretched.
(ii) State the main method of energy transfer when the rubber band is stretched.
(iii) State the source of the energy transferred to the rubber band.
(b) The diagram shows a force-extension graph for a rubber band.
(i) State how the graph shows that the rubber band does not obey Hooke’s law.
(ii) Explain how the graph shows that the rubber band is elastic.
(c) The student stretches the rubber band and then releases it. The band moves vertically upwards.
(i) The band travels with an initial speed of 13m/s. When the band reaches its maximum height above the student’s hand, the band has a speed of 0m/s. Calculate the maximum height that the band reaches. Give your answer to 2 significant figures.
[acceleration due to gravity = −10m/s²]
(ii) The band reaches its maximum height. Explain the motion of the band as it falls from its maximum height to the ground. Refer to forces in your answer. You may assume
• the band does not rotate
• the band does not reach terminal velocity
▶️Answer/Explanation
Ans
(a) (i) elastic (potential) / EPE;
(ii) mechanically/mechanical (working);
(iii) the person/the hand/the fingers;
(b) (i) curve/variable gradient/not linear;
(ii) line returns to {origin/start/(0,0)/no extension};
when the force is removed/ unloaded;
(c) (i) substitution into given equation “v2 = u2 + 2as”;
re-arrangement;
evaluation;
answer to 2 sig figs;
e.g.
\(0^2 = (13)^2 + (2 × -10 × s)\)
height = 169 / 20
(height =) 8.45 (m)
(height =) 8.5 (m)
(ii) any five from:
MP1. band has weight;
MP2. no drag at highest point;
MP3. resultant force is downwards;
MP4. band accelerates;
MP5. (once band is moving) there is drag
MP6. drag increases (while accelerating);
MP7. resultant force decreases;
MP8. (so) acceleration decreases;
Questions 10
(a) Topic – 2.b
(b) Topic-2.b
(c) Topic-2.b
Diagram 1 shows a generator inside a small wind turbine. The generator is connected to a lamp and the windmill blades.
(a) When the coil rotates in the direction of the arrow, the ammeter displays a small current. Explain how the generator produces a current.
(b) The generator in the wind turbine acts as an alternating current (a.c.) power supply. Diagram 2 shows an electric circuit containing the generator being used to charge a mobile phone battery.
(i) Direct current (d.c.) is needed to charge the battery. Explain why there is a diode in the circuit.
(ii) Explain how the current in the battery will change if the wind speed increases.
(c) The mean voltage across the battery is 7.2V. The battery gains 14kJ of energy in 8400 seconds. Calculate the mean current in the battery.
▶️Answer/Explanation
Ans
(a) (coil rotates) through magnetic field / cutting field lines;
voltage is induced;
(b) (i) idea that d.c. is current in one direction only;
diode allows current flow in one direction only/eq;
(ii) higher speed generates higher voltage;
higher voltage causes higher current;
(c) substitution into given equation ‘E = IVt’;
rearrangement;
evaluation;
e.g.
14 000 = I × 7.2 × 8400
(current =) 14000 / (7.2 × 8400)
(current =) 0.23 (A)
Questions 11
(a) Topic – 6.d
(b) Topic-6.d
This question is about gas pressure.
(a) Diagram 1 shows some of the molecules of a gas in a sealed container.
The molecules collide with all the surfaces of the container. This exerts an outward force on the container and causes pressure. Describe how the motion of the gas molecules causes an equal pressure on all the walls of the container. You may add to diagram 1 to help your answer.
(b) The width of the container is slowly decreased so that the volume of the container is smaller than before. Diagram 2 shows the width of the container before and after this change. All other dimensions of the container remain the same.
The initial volume of the gas is \(130cm^3\). The initial pressure of the gas is 100kPa. Calculate the pressure of the gas after the width of the container is decreased. Assume the temperature of the gas remains constant.
▶️Answer/Explanation
Ans
(a) idea that (large number of) molecules moving randomly;
idea of equal rate of collisions in each direction;
(b) evaluation of new volume;
substitution into \(p_1V_1 = p_2V_2\);
rearrangement;
evaluation of new pressure;
e.g.
\(V_2 = (130 × 5.0/8.4 =) 77 (cm^3)\)
100 × 130 = \(p_2\) × 77
\((p_2 =)\) 100 × 130/77
\((p_2 =)\) 170 (kPa)
Questions 12
(a) Topic – 3.b
(b) Topic-3.b
Air is trapped in a boiling tube by sealing the boiling tube with a rubber bung. The boiling tube is placed in a beaker containing hot water.
(a) Energy is transferred from the thermal store of the water to the thermal store of the air in the boiling tube with an efficiency of 16%. The air in the boiling tube gains 1800 J of energy during this process. This is defined as the useful energy transfer. Calculate the amount of energy wasted during this process.
(b) Give two ways that the apparatus could be modified to improve the efficiency of the energy transfer.
▶️Answer/Explanation
Ans
(a) substitution into given equation,
\(efficiency = \frac{useful \ output \ energy } {total \ output \ energy}(\times 100 %)\);
rearrangement;
evaluation of total output energy;
evaluation of wasted energy;
e.g.
0.16 = 1800/total output
total output = 1800 / 0.16
total output = 11250 (J)
(wasted energy = 11250 – 1800 =) 9500 (J)
(b) any two from: 2
MP1. wrap beaker in insulation;
MP2. cover top of beaker;
MP3. fully immerse boiling tube in water;
MP4. shiny outer layer to the beaker;
MP5. use a thinner (walled) boiling tube
MP6. use a better conducting boiling tube