Physics 9203 | Paper 1 Mock 01 | Written Paper 1

The table below shows radiation data from two red giant stars measured by a space telescope. Fig. 1 represents the same stars as circles, drawn to scale only for relative size.

(a) What is the surface temperature of K? [1]
(b) Describe two differences between J and K. [3]
(c) Explain why J has a greater luminosity than K. [4]
(d) Give two observations that would support the classification of J as a red giant. [2]
(e) Name the likely remnant of J if it began with a mass similar to the Sun. [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]

The diagram shows a road safety worker examining a raised cat's-eye marker. A car headlamp shines on one face of the marker. Inside, two reflective faces meet at a right angle. The returned light is seen by the driver even when rain makes the road surface dark. The worker compares the marker with a flat strip of reflective tape.

(a) Describe the path of the ray inside the marker. [2]
(b) Explain why the driver receives light back from the marker. [2]
(c) Give one advantage of this marker over a plane mirror fixed at one angle. [2]

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]

A museum conservator uses a small solar-powered motor to turn a mirror that directs light from the sun onto a display case. Fig. 1 shows the motor. A coil is fixed to an axle between the poles of two permanent magnets. The solar panel provides a potential difference of 6.0 V. Current enters the coil through carbon contacts. The split ring changes the connections to the coil after each half-turn, so that the mirror continues to rotate about its pivot.

(a) Name the parts labelled X and Y in Fig. 1. [2]
(b) Describe the energy transfer that takes place while the motor turns the mirror. [2]
(c) Explain why the coil experiences a turning effect when current flows through it. [3]
(d) Calculate the electrical power supplied to the motor when the current is 0.40 A. State the unit of your answer. [3]

A wildlife photographer has difficulty focusing on a hawk flying far away after spending an hour editing close-up pictures on a screen. Fig. 1 shows the eye when viewing the close screen. Ciliary muscles are shown around the lens. The photographer's eye automatically changes the shape of the lens so that light from the object is focused on the retina. This automatic adjustment is called accommodation. The photographer then looks from the screen to the hawk without moving the head.

(a) Describe the shape of the lens when the screen is close. [1]
(b) Explain how the ciliary muscles and lens change when the photographer looks at the distant hawk. [3]
(c) Give the name of the process described. [1]

A technician calibrates a projector used to display a large safety diagram in a factory training room. Fig. 1 shows the object slide, a convex lens and a wall screen. The slide is placed beyond twice the focal length of the lens. The diagram on the screen must be sharp enough for workers to read warning signs from the back of the room. The technician adjusts the lens position along a rail before the session begins. Light from the bright slide passes through the lens and forms an image on the wall.

(a) Describe the orientation of the projected image. [1]
(b) Explain why the wall must be placed at the position where rays meet. [2]
(c) Give two changes needed if the image on the wall is not sharp. [2]

Fig. 1 shows an observatory poster about the Sun. The central core contains hot plasma, not solid material. The poster states that energy travels outward before leaving as light and other waves.

(a) Name the nuclear process in the core. [2]
(b) Give the two particles that combine in the main fusion reaction. [2]
(c) Explain why this reaction needs an extremely high temperature. [3]
(d) Describe two useful effects of energy from the Sun on Earth. [3]

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]

Fig. 1 shows a museum conservator using a tiny electric heater to dry a damp display case after a leak. The heater transfers 18 000 J of electrical energy in 5.0 minutes. Its potential difference is 12 V. The conservator records the energy because heat could damage an old paper object. A battery pack supplies the heater through a short cable. The diagram shows that the heater is separate from the small fan, which moves warm air around the case.

(a) Complete the calculation of the heater power. [2]
(b) Give the current supplied to the heater. [2]
(c) Name the unit of electrical energy used in this question. [1]

Fig. 1 shows a school caretaker replacing a faulty doorbell transformer. The transformer reduces the 230 V mains potential difference to 8.0 V for the bell circuit. The bell takes a current of 0.40 A and rings for a total of 25 s during a busy morning. The transformer has two coils wound around an iron core. This makes the doorbell safer to use near a metal entrance panel than connecting the bell directly to the mains.

(a) Name the component that reduces the potential difference. [1]
(b) Give the power transferred to the bell. [2]
(c) Complete the calculation of energy transferred while the bell rings. [2]

The diagram shows a mechanic using a heated metal ring to fit it around a railway wheel. At first, the ring is slightly too small. The mechanic heats it evenly, places it over the wheel, and then allows it to cool. The wheel and ring are both solid objects, but their particles vibrate more when their temperature rises.

(a) Describe what happens to the spacing between particles in the ring when it is heated. [1]
(b) Explain why the ring diameter increases. [2]
(c) What happens to the ring when it cools around the wheel? [1]

A child looks through a cardboard kaleidoscope at a science festival. Fig. 1 is a cross-section of the tube. Three plane mirrors make a triangular arrangement, and coloured pieces at one end scatter light into the tube. Multiple reflections produce a repeating pattern. The child turns the tube slowly and sees the pattern change, although the positions of the mirrors remain fixed.

(a) What causes the repeated images in the pattern? [1]
(b) Describe what happens to a ray each time it meets a mirror surface. [2]
(c) Explain why turning the tube changes the pattern. [2]

Fig. 1 shows a maintenance worker using a small periscope to look over a storage wall. Inside the box are two plane mirrors. A ray of light from an object outside the wall reflects from mirror A and then from mirror B before reaching the worker's eye. The mirrors are parallel, so the worker can see the object without moving to a higher point.

(a) Name the type of reflection produced by each smooth mirror. [1]
(b) Describe the path of the light ray after it reaches mirror A. [2]
(c) Explain why the worker sees an upright image of the object. [1]