Questions 1
(a) Topic – 9.c
(b) Topic-9.c
(c) Topic – 9.c
(d) Topic – 9.c
This question is about stars. The diagram shows an incomplete Hertzsprung-Russell (H-R) diagram.
(a) Label the axes on the diagram.
(b) There are three shaded areas on the diagram. State the name of the shaded area that contains the Sun.
(c) Which star is a white dwarf?
A
B
C
D
(d) At a standard distance from the Earth, which star is brighter than the Sun and has a greater surface temperature than the Sun?
A
B
C
D
▶️Answer/Explanation
Ans
(a) y-axis: one from
• luminosity;
• absolute magnitude;
• power;
x-axis: one from
• temperature;
• colour;
• spectral class;
(b) main sequence;
(c) B;
A is incorrect because it is a red giant
C is incorrect because it is a hot main sequence star
D is incorrect because it is a cool main sequence star
(d) C;
A is incorrect because red giants are cooler than the Sun
B is incorrect because white dwarf stars are fainter than the Sun
D is incorrect because this star is both cooler and fainter than the Sun
Questions 2
(a) Topic – 8.c
(b) Topic-8.c
This question is about nuclear fission and nuclear fusion.
(a) The table gives some statements about nuclear fission, or nuclear fusion, or both nuclear fission and nuclear fusion. Place ticks in the table to show which statements are about nuclear fission and which statements are about nuclear fusion.
(b) Nuclear fission reactors use control rods and a moderator. Describe the function of the control rods and the function of the moderator in a nuclear fission reactor.
▶️Answer/Explanation
Ans
(a) one mark for each correct row;;;
(b) control rods absorb neutron(s);
moderator reduces speed of neutron(s);
Questions 3
(a) Topic – 4.c
(b) Topic-4.c
A sample of liquid gallium is allowed to cool in a laboratory. The liquid gallium freezes to become a solid.
(a) Complete the diagram by drawing the arrangement of particles in a liquid and the arrangement of particles in a solid. The first particle in each box has been drawn for you.
(b) The initial temperature of the sample of liquid gallium is 80°C. The freezing temperature of gallium is 30°C. The final temperature of the solid gallium is 20°C. Complete the graph to show how the temperature of the gallium changes during the time that it cools to 20°C. Add appropriate values to the temperature axis.
▶️Answer/Explanation
Ans
(a) liquid arrangement:
attempt to draw most particles in contact with each other;
random arrangement;
solid arrangement:
attempt to draw particles in contact with each other;
regular arrangement;
(b) line drawn decreasing from any high temperature to any low temperature;
single constant temperature stage drawn in the middle of the cooling (to show freezing);
temperature axis labelled with suitable values e.g. line starts at 80, flat stage at 30 and line ends at 20;
Questions 4
(a) Topic – 7.d
(b) Topic-7.d
The photograph shows transmission cables used for long-distance transmission of electricity.
(a) The diagram shows a power station and a school. Add to the diagram by drawing the structures needed to efficiently transfer energy from the power station to the school using electricity.
(b) Explain how the amount of current in the transmission cables increases the efficiency of the transmission of electricity.
▶️Answer/Explanation
Ans
(a) at least one transformer drawn in the space between power station and school;
second similar object drawn in the space between power station and school;
transformer/object nearest power station labelled “step-up” and transformer/object nearest school labelled “step-down”;
(b) (because) current causes wires/cables to heat up;
idea of low/decreased/less current;
reduces energy loss (to the surroundings);
Questions 5
(a) Topic – 1.c
(b) Topic-1.c
(c) Topic – 1.c
(d) Topic – 3.c
The diagram shows the collision between two balls, A and B. The masses and velocities of both balls are shown before and after the collision. Ball B is stationary before the collision.
(a) When the balls collide, ball B applies a force on ball A, which causes the velocity of ball A to change. Ball A also applies a force on ball B during the collision. Describe how the force applied on ball A compares with the force applied on ball B during the collision.
(b) Calculate the momentum of ball A before the collision.
(c) Show that the velocity, v, of ball B after the collision is about 0.6m/s.
(d) A collision is considered elastic if the total kinetic energy before the collision is equal to the total kinetic energy after the collision. Using data from the diagram, deduce whether this collision is elastic.
▶️Answer/Explanation
Ans
(a) both forces are the same size/magnitude/equal;
forces are in opposite directions;
(b) substitution into p = m × v;
evaluation;
e.g.
(momentum =) 0.018 × 4.9
(momentum =) 0.088 (kg m/s)
(c) use of conservation of momentum;
setting up equation to be solved;
rearrangement;
evaluation to 2 or more significant figures;
e.g.
momentum is conserved
0.088 = 0.018 × −3.5 + 0.265 × v
v = [0.088 + 0.063]/0.265
v = 0.57 (m/s)
(d) use of KE = \(\frac{1}{2} \times m \times v^2\);
evaluation of KE before collision;
evaluation of KE after collision;
comparison with correct conclusion that collision is not elastic/inelastic;
Questions 6
(a) Topic – 3.d
(b) Topic-3.d
This question is about generating electricity from renewable energy resources.
(a) Photograph 1 shows a solar farm in the United Kingdom and photograph 2 shows a geothermal power station in Iceland.
Discuss the advantages and disadvantages of generating electricity using solar power and geothermal resources
(b) A student investigates how the amount of light affects the output voltage of a solar cell. Photograph 3 shows how the student sets up their equipment
(i) The student varies the distance between the solar cell and the lamp and measures the output voltage of the solar cell at each distance. The student’s results are shown below. 
Draw a table showing the student’s results.
(ii) Give a control variable for the student’s investigation.
(iii) The student states that the solar cell could be used as a power source for the lamp. They suggest that this would work if
• the solar cell is connected directly to the lamp
• the light from the lamp is used to produce the output power from the solar cell
Explain, with reference to the principle of conservation of energy, why the student’s suggestion would not work.
▶️Answer/Explanation
Ans
(a) any one advantage for solar:
• produces no noise;
• available in all locations;
• no greenhouse/polluting/harmful gases produced;
any one disadvantage for solar:
• dependent on amount of sun(light);
• requires large area of panels;
any one advantage for geothermal:
• can be used all day;
• requires small amount of space;
• produces very little/no noise;
any one disadvantage for geothermal:
• not available in all locations;
• releases some greenhouse/polluting/harmful gases;
• possible pollution of ground water;
(b) (i) two columns/rows with headings of “distance” and “voltage”;
units included correctly in both column headings;
all data recorded correctly to the same number of decimal places as originally presented;
(ii) any one of:
• power/luminosity (of lamp);
• (amount of) background light;
• brightness of lamp;
• light intensity of lamp;
(iii) any two from:
MP1. idea that lamp / solar cell is not 100% efficient;
MP2. not all light produced by lamp is received by solar cell;
MP3. energy losses {in connecting wires / to surroundings / as heat};
Questions 7
(a) Topic – 5.d
(b) Topic-5.d
The diagram shows two students doing an experiment to measure the speed of sound in air.
This is their method.
• both students stand 100 m away from a large flat wall
• student A makes a sound by hitting two blocks of wood together
• the sound waves travel to the wall and reflect back to the students as an echo
• student A hits the blocks together again when the echo is heard
• student A continues to hit the blocks together every time an echo is heard
• student B starts a timer when the blocks are hit together and stops the timer
when the blocks have been hit together 20 more times
(a) Give a reason why the students do not stand nearer to the wall.
(b) The students repeat their method five times. The table shows the students’ results.
(i) The students decide that one of their tests shows an anomalous result. Circle the anomalous result in the table.
(ii) Suggest a reason for the anomalous result.
(iii) Calculate the mean time between starting and stopping the timer. Give your answer to a suitable number of decimal places.
(iv) The speed of sound in air can be calculated using the formula
\(speed=\frac{distance \ travelled}{time \ taken}\)
Use the students’ results to calculate a value for the speed of sound in air.
▶️Answer/Explanation
Ans
(a) idea that time (between hits) is too short / reaction/thinking time is an issue;
(b) (i) 11.18 circled;
(ii) idea that student miscounted the number of block hits;
(iii) evaluation of a mean value;
evaluation of a mean value excluding anomaly;
final answer correctly given to 2 decimal places;
e.g.,
mean = 11.642 (s)
mean = 11.7575 (s)
mean = 11.76 (s)
(iv) substitution into given formula;
evidence of doubling distance OR dividing time by 20;
evaluation;
e.g.
speed = (2×) 100 / 11.76(÷20)
distance = 200m OR time = 0.59s
speed = (200 / 0.59) = 340 (m/s)
Questions 8
(a) Topic – 5.b
(b) Topic-5.c
The diagram shows a machine that can be used to measure the speed of fast-moving protons.
(a) At the start, the proton is attracted towards a negatively charged plate.
(i) Give a reason why the proton is attracted to the negatively charged plate.
(ii) The proton accelerates at \(1.90 × 10^{11}\) m/s² from rest to a speed of \(1.38 × 10^5 m/s\). Show that the time taken for this acceleration is about 7 × 10⁻⁷ s.
(b) The proton passes through a hole in the negatively charged plate and enters an area where there is a magnetic field. The magnetic field exerts a force on the proton, as shown in the diagram. This force causes the proton to follow a circular path without changing speed.
(i) Give the direction of the magnetic field.
(ii) Suggest how increasing the strength of the magnetic field will affect the proton when it is moving in the magnetic field.
▶️Answer/Explanation
Ans
(a) (i) idea that proton and plate have opposite charges;
(ii) substitution into a = (v-u)/t;
rearrangement;
evaluation to 2 s.f. or more;
e.g.
\(1.90 × 10^{11} = 1.38 × 10^5 / t\)
\(t = 1.38 × 10^5 / 1.90 × 10^{11}\)
t = 7.26… × 10⁻⁷(s)
(b) (i) into the page / eq;
(ii) any two from: 2
idea that force increases;
acceleration increases;
proton moves in tighter circle / hits detector further to the left;
Questions 9
(a) Topic – 5.b
(b) Topic-5.b
(c) Topic-5.b
An oscilloscope can be used to determine the frequency of a sound wave.
(a) Give the name of the piece of apparatus that must be connected to the oscilloscope to detect the sound wave.
(b) The diagram shows the screen of the oscilloscope and the oscilloscope settings.
A sound wave of frequency 250Hz is detected. The sound wave produces a trace on the oscilloscope of amplitude 4V. Complete the diagram by drawing the trace of this sound wave on the oscilloscope screen
(c) The graph shows how the wavelength of sound waves in air varies with their frequency.
If wavelength and frequency are inversely proportional, then
wavelength × frequency = constant
Using the graph, evaluate whether the wavelength of sound waves in air is inversely proportional to their frequency.
▶️Answer/Explanation
Ans
(a) microphone;
(b) any roughly sine-shaped wave drawn on the screen;
amplitude of trace = 2 squares;
substitution into f = 1 / T;
evaluation of time period = 0.004 (s);
trace drawn on oscilloscope has period of 4 squares;
(c) single use of data from graph to show that
frequency × wavelength = constant;
second use of data from graph to show that
frequency × wavelength = constant;
clear comparison of constants to show they are (approximately) equal AND conclusion that the relationship is inversely proportional;