Physics 9203 | Paper 1 Mock 01 | Written Paper 1

The diagram shows the reflector behind the bulb in a hand torch. The bulb is placed at the focus of a concave reflecting surface. Light that would otherwise travel backwards reflects from the surface and leaves the torch in an approximately parallel beam. This concentrated beam helps a walker see a path at night without using a high current from the battery.

(a) Name the reflector shape. [1]
(b) Describe the direction of reflected rays leaving the torch. [2]
(c) Explain why placing the bulb away from F makes the torch beam less useful. [2]

Fig. 1 shows part of a reflecting telescope at an observatory. Light from a distant star enters the open end as nearly parallel waves. A large concave primary mirror reflects the light towards a smaller plane mirror. The plane mirror sends the light sideways into an eyepiece. The telescope avoids a glass lens at the front, so there is no colour separation caused by refraction.

(a) What does the primary mirror do to the incoming parallel light? [1]
(b) Describe the role of the small plane mirror. [2]
(c) Give one reason why the primary mirror must have a very smooth surface. [2]

A designer tests a spring door closer in a library. Fig. 1 shows the door held open. A spring inside the closer is twisted when the door is opened. When released, the door returns slowly to the frame. The closer is filled with oil, so the door does not slam. The designer wants the system to be safe while avoiding excessive sound and heating.

(a) Name the energy store that increases as the door is opened. [1]
(b) Explain how the oil helps prevent the door from slamming. [2]
(c) Give two unwanted energy transfers as the door closes. [2]

Fig. 1 shows a technician testing a solar cooker made from a reflective dish. Light from the sun is focused onto a black cooking pot. The pot contains 0.80 kg of water. During a test, the water temperature rises by 15 degrees C. The specific heat capacity of water is 4200 J/kg degrees C. The technician wants to compare the useful energy gain of the water with energy arriving from the sun.

(a) Name the useful energy store that increases in the water. [1]
(b) Calculate the energy gained by the water. [2]
(c) Give two reasons why not all of the light energy from the sun becomes useful energy in the water. [2]

Fig. 1 shows a speed-time graph produced by a motion sensor on an electric tram. The tram leaves a station, moves along a straight track, and then brakes before the next platform. Point P is at 20 s. The driver keeps passengers comfortable by avoiding sudden changes in velocity. The graph uses speed rather than velocity because the tram does not reverse direction during this journey.

(a) Name the type of graph shown in Fig. 1. [1]
(b) Describe the tram's motion between point P and the start of braking. [2]
(c) What does the downward sloping line show about the tram's speed? [2]
(d) Give the equation linking acceleration, change in velocity and time. [2]
(e) Explain why passengers move forwards relative to the tram when it brakes. [3]

Fig. 1 shows two divers communicating underwater using a signal device. Diver A strikes a metal plate to make a sound pulse. Diver B receives the pulse 0.20 s later at a distance of 300 m. The divers cannot rely on ordinary speech over this distance because the equipment masks their voices and the water is noisy. The diagram shows the pulse travelling directly through seawater. The divers compare this result with sound travelling through air. Their instructor reminds them that wave velocity depends on the medium, while frequency is set by the source.

(a) Calculate the velocity of sound in the seawater. [2]
(b) Explain why sound can travel through seawater. [2]
(c) What happens to the frequency of the pulse when it enters the water from the metal plate? [1]
(d) Give one reason why a short pulse is useful for communication. [1]

Fig. 1 shows a comparison board at a science museum. It compares a fission reactor with a fusion reactor. Both are nuclear energy sources, but the fission reaction splits a heavy nucleus whereas fusion joins light nuclei. Visitors are asked to consider the source of fuel and the long-term radioactive waste before choosing which technology may be more useful.

(a) Name the reaction shown in the right-hand box. [1]
(b) Give one similarity between fission and fusion. [1]
(c) Describe one advantage of fusion fuel compared with uranium fuel. [1]
(d) Explain one reason why fusion may produce less long-lived radioactive waste than fission. [2]

Fig. 1 is a binding-energy-per-nucleon graph used by a research team choosing possible reactor fuels. The vertical axis shows how strongly nucleons are held in a nucleus. Deuterium and tritium are light hydrogen isotopes. Iron is near the highest point on the graph. The team wants a reaction with an energy output that is useful for generating electricity.

(a) Name the type of nuclear reaction represented by moving from deuterium towards helium. [1]
(b) Describe how Fig. 1 shows that energy is released in this reaction. [2]
(c) Explain why fission of a very heavy nucleus can also release energy. [2]

A child watches an animation in a planetarium. Fig. 1 shows the orbit of a fictional planet around its star. At P the planet is closest to the star, and at Q it is furthest away. The animation uses a line of light to show one complete path. The presenter says that the planet's velocity is not constant throughout the orbit, even though it returns to the same point each year.

(a) What is the name of the path followed by the planet? [1]
(b) Describe the difference between the planet's speed at P and at Q. [1]
(c) Explain why the planet changes direction as it moves around the star. [2]

The diagram shows a kitchen toaster being examined after it stopped heating. The toaster is rated at 1.8 kW and uses a 230 V supply. Its heating element is a coil of high-resistance wire. When current passes through the coil, the element becomes hot enough to toast bread. A technician finds that the coil is broken at one point. The toaster also has a plastic outer case and a metal crumb tray.

(a) Explain why the heating element is made from a material with high resistance. [2]
(b) Calculate the current in the toaster when it is operating normally. [2]
(c) Give one reason for using a plastic outer case. [1]

A smoke alarm in a rented house is powered by a 9 V battery. Fig. 1 shows the battery connected to a buzzer and a switch operated by smoke particles. When the switch closes, current flows through the buzzer and sound waves warn the residents. During a monthly check, the alarm makes only a faint sound. The landlord replaces the battery rather than bypassing the warning device.

(a) Name the component that provides the potential difference in this circuit. [1]
(b) Describe the energy changes in the buzzer when the alarm operates. [2]
(c) Explain why a weak battery can make the sound quieter. [1]

Fig. 1 shows a skateboard rolling towards a ramp in a sports hall. A motion sensor records the skateboard's speed just before it reaches the ramp. The board and rider have a combined mass of 55 kg and move at 3.0 m/s. The rider then rolls up the ramp and comes briefly to rest at a higher point. The coach discusses how motion changes when gravitational potential energy increases.

(a) Give the momentum of the rider and skateboard just before the ramp. [2]
(b) Describe what happens to the skateboard's velocity as it travels up the ramp. [2]
(c) Explain why the skateboard eventually stops on the ramp. [1]

The engineering log from a deep-sea survey vessel includes the energy route shown in Fig. 2. Its compact reactor allows the vessel to operate far from fuel ports. Inside the reactor, fission releases energy from nuclear fuel. A separate loop carries this energy to a steam unit, which drives a turbine and generator. The generator supplies a motor through a cable at a potential difference of 4.0 kV. The motor turns the propeller and gives the vessel velocity through the water.

During one hour, the reactor releases 8.0 × 10⁸ J of energy. The useful energy delivered to the propeller is 2.0 × 10⁸ J.

(a) What store provides the original energy in the reactor fuel? [1]
(b) Complete the energy pathway for Fig. 2 using suitable energy stores or transfers: nuclear store → ............ → kinetic store of turbine → ............ → kinetic store of propeller. [3]
(c) Explain why the vessel uses a separate coolant loop rather than sending water from the reactor core directly to the turbine. [3]
(d) Calculate the efficiency of the energy transfer from reactor fuel to the propeller. [2]
(e) Give two reasons why a nuclear-powered vessel can be useful on a long survey voyage. [2]

A motorway passes close to a row of homes. Fig. 1 shows a proposed noise barrier placed between the road and one garden. Engineers compare a thin wooden fence with a taller barrier made from dense concrete. Sound from car engines, tyres and horns can travel over or around a barrier. The homes are 40 m from the road. The engineers want a design that reduces the sound energy reaching the garden without blocking the drivers' view at a junction. The diagram shows the direct path and a possible diffracted path of sound waves.

(a) Give one source of sound from the motorway. [1]
(b) Explain why a taller barrier can make the garden quieter. [2]
(c) Which material, wood or dense concrete, should be chosen for the barrier? [1]
(d) Describe what happens to the sound energy when it reaches the concrete. [1]

The diagram shows a microphone connected by a cable to an oscilloscope during a school sound investigation. A pupil speaks the same word at a quiet and then a louder level, standing 1.0 m from the microphone. Two traces are displayed. Each horizontal division represents 1 ms. The potential difference from the microphone changes because its diaphragm vibrates. Trace A has a smaller vertical height than trace B, while the spacing of their peaks is the same. The pupil uses the figure to compare loudness without changing the sound source.

(a) Name the component that changes sound vibrations into an electrical signal. [1]
(b) What feature of trace B shows that the sound is louder? [1]
(c) Explain why both traces have the same pitch. [2]
(d) Give the unit used for the time scale on this oscilloscope. [1]

A dentist uses a small circular mirror to inspect a patient's back tooth. Fig. 1 shows the mirror held close to the tooth. The dentist wants the image to be upright and larger than the actual object so that a crack in the enamel can be seen clearly. The mirror is part of a handle and has a polished curved surface.

(a) Name the type of curved mirror shown. [1]
(b) Explain why the tooth must be placed between the mirror and point F to obtain the required image. [2]
(c) Give one difference between the image and the tooth, apart from its size. [1]

The diagram shows a cyclist's helmet visor with an anti-glare coating. Light from a low sun reflects from the front and back surfaces of the thin coating. The coating is designed so that some reflected light waves cancel, reducing glare. This question considers the reflection of light, not the sound waves or the potential difference in the bicycle lamp circuit.

(a) Name the law that relates the angle of incidence to the angle of reflection at either surface. [1]
(b) Give one benefit of reducing reflected sunlight for the cyclist. [1]
(c) Describe the type of image that would be formed by a smooth flat visor surface. [1]