OCR GCSE Physics B (21st Century) Paper 4 June 2023 question paper

A student investigates the path of light passing through a triangular glass prism.

A narrow beam of white light is directed at the prism with an angle of incidence equal to 40°. The student observes a spectrum of different coloured light.

The two-dimensional diagram shows a narrow beam of white light directed at the side of a prism.

A line showing the path of a ray of blue light passing through the prism is partially drawn.

Complete the line to show the path of blue light as it passes out the other side.

Estimate the size of the angle of refraction of the ray of blue light as it enters the prism.

Add another line to the diagram to show the path of a ray of red light as it passes through

the prism and out the other side.

Jamal is making a model aeroplane that can be launched from a moving trolley.

One end of a spring is connected to the trolley. The other end of the spring is held stationary.

The aeroplane is placed on the trolley. Jamal pulls the trolley and the aeroplane to the right so that the spring stretches. When Jamal lets go, the trolley and the aeroplane accelerate to the left.

Explain how Jamal can make the trolley and aeroplane accelerate more quickly using the same apparatus.

Jamal investigates the relationship between force and extension for the spring. The results of the investigation are shown in the table and the graph.

* Describe how Jamal gets these results safely and how he uses the results to calculate the work done in stretching the spring.

The kinetic energy of the trolley must be at least 1 J for the aeroplane to launch from the trolley.

Jamal concludes that the aeroplane can launch from the trolley when the spring has an extension of 0.16 m.

Use the graph to explain why Jamal’s conclusion is wrong.

Jamal investigates using a ramp instead of a spring to launch the aeroplane.

Jamal releases the trolley and the trolley accelerates down the ramp. The aeroplane is launched when the trolley reaches the bottom of the ramp.

Describe how Jamal can accurately measure the speed of the trolley at the bottom of the ramp.

You should include the equipment Jamal uses.

A ball is placed in a dark room. White light from a lamp is shone on the ball. The ball appears yellow.

A green filter is placed between the lamp and the ball.

Explain why the ball appears green.

Which two statements are correct about green light?

Tick (✓) two boxes.

The ball is placed inside a bell jar and the air is removed.

Explain why the ball can still be seen when there is no air in the jar.

Compare the structures of the nuclei of actinium-225 and actinium-227.

State why a nucleus might decay.

Name the electromagnetic radiation that is emitted in both cases.

Name one other ionising radiation emitted in each case.

The table shows some data for the thinking distance, braking distance and stopping distance of a car travelling at different speeds.

When the speed doubles, the thinking distance doubles, and the braking distance quadruples.

Use this information to complete the table.

A student concludes that the stopping distance must be at least triple when the speed doubles.

Use data from the table to explain why the student is correct.

Convert 40 miles per hour to m / s.

1 mile = 1609 m.

40 miles per hour =........ m / s

Estimate the typical speed of a cyclist in m / s.

Sara is investigating magnetism. She suspends a small bar magnet from a length of cotton as shown in Fig. 6.1.

The magnet hangs horizontally and can rotate freely.

Explain why the magnet will always come to rest lying in the same direction.

Sara has a second magnet with the north and south poles labelled. She brings it up close to the suspended magnet in Fig. 6.1.

Explain how she can identify the poles of the suspended magnet.

Sara investigates the magnetic field around a wire which has a current passing through it.

She puts the wire through a horizontal piece of card. From her investigation she draws field lines to show the pattern of the magnetic field around the wire as shown in Fig. 6.2.

Suggest a method Sara uses to observe the pattern of the magnetic field.

Draw an arrow on Fig. 6.2 to show the direction of the magnetic field.

Describe how the field lines in Fig. 6.2 show that the strength of the magnetic field decreases as the distance from the wire increases.

Sara increases the size of the current in the wire.

Explain how the pattern of the field lines changes.

Describe how Sara can use the motor as a generator.

Sara replaces the split ring commutator with slip rings.

Describe how the output of the generator changes.

7* Uranium (U) and hydrogen (H) can be used to release energy in a nuclear reaction.

Typical nuclear equations for each are:

Compare and contrast these two processes, explaining how energy is released in both cases.

A metal disc has a weight of 4.0 N. The disc is suspended from a spring and the extension of the spring is measured. The measurement is made three times.

The results are shown in the table.

Calculate the spring constant of the spring.

Give your answer to 2 significant figures.

Use the Equation Sheet.

Spring constant =........ N / m

The disc is placed flat on a smooth surface. Two perpendicular forces, 2 N and 3 N, are applied to the disc parallel to the surface, as shown in Fig. 8.1 when viewed from above.

Fig. 8.1 is not to scale.

Draw a scale diagram to find the size of the resultant force on the disc.

Use the scale 1 N = 2 cm

The centre of the disc is pinned to the surface. The disc can rotate but its position on the surface cannot change.

Two forces are applied to the disc as shown in Fig. 8.2.

Explain how these two forces cause the disc to rotate about its centre.

Li makes wax candles.

Li needs to calculate the specific heat capacity of the wax.

Name two other pieces of equipment that are needed so Li can calculate the specific heat capacity, and describe what each piece of equipment is used for.

Explain how the calculated value for the specific heat capacity would be different if the beaker was not insulated.

Explain why it is important that Li does not exceed the melting point of the wax.

In a different investigation Li connects a 12 V d.c. power supply to a heater. 0.02 kg of wax is heated.

The temperature of the wax increases by 18 °C in 120 s.

Calculate the current in the heater.

The specific heat capacity of the wax is 2890 J / kg °C.

Use these equations:

• change in internal energy = mass × specific heat capacity × change in temperature

• power = energy ÷ time

• power = potential difference × current

Li designs an electric heater using nichrome wire.

Li connects the wire in a circuit with a power supply, an ammeter and a voltmeter. He makes measurements and calculates the resistance of different lengths of the wire.

He produces a graph as shown.

Describe how Li calculates the resistance of different lengths of the wire.

Your answer should include a circuit diagram.

Suggest why Li switches off the power supply between each measurement.

Li uses a length of the nichrome wire as a heater connected to a different power supply.

This heater supplies a power of 20 W when the current is 2.5 A.

Calculate the length of the wire.

Use the Equation Sheet and the graph.