OCR GCSE Physics B (21st Century) Paper 1 June 2025 question paper

A student is experimenting with an iron nail and a bar magnet.

First, they place a paper clip close to the iron nail.

The nail does not attract the paper clip.

Then they place a bar magnet touching the end of the nail.

The nail now attracts the paper clip, so the paper clip is attached to the nail.

Which of these is a correct description of the nail ?

Tick (✓) one box.

What happens to the paper clip when the bar magnet is taken away?

Tick (✓) one box.

Paperclips can be made from different metals.

Which two of these metals could the paperclip in this experiment be made from?

Tick (✓) two boxes.

The diagram shows the magnetic field around a bar magnet.

Complete the table to show the property of a magnetic field that is shown by each feature of the diagram.

Tick (✓) one box in each row.

Explain why a magnetic compass can be used to support the idea that the Earth’s core is magnetic.

Kettles are used to heat water to boiling point.

What is the useful output energy store of a kettle?

Tick (✓) one box.

The table shows some electrical information about a mains electric kettle used at home and a travel kettle.

Which piece of information gives the power rating of the mains electric kettle?

Tick (✓) one box.

Both kettles are used to boil the same volume of water.

Complete the sentence to explain the time taken for each kettle.

Use words from the list.

energy frequency less

more
temperature the same

The travel kettle will take........ time to boil the water because it transfers

less........ per second.

Hot water is poured from a kettle into an insulated flask.

The water fills the flask.

The lid is screwed on.

The diagram shows a cross-section through the flask.

The water stays hot in the flask.

Complete the sentences to describe this flask system.

Use words from the list.

closed changing constant

decreased increased open

The flask system stays at the same temperature because the total energy

is........

This means the flask system can be referred to as........

Some household appliances are operated for a longer time than a kettle.

Which of these is the correct calculation to find the energy transferred, in kWh, when a 1500 W appliance is used for 2 hours?

Use the equation: energy transferred = power × time

Tick (✓) one box.

The table shows data about four household appliances.

Complete the sentences to describe the energy transfer of the appliances.

The wasted energy store of the desk fan is electrical / kinetic / thermal energy.

The lamp transfers energy to the surroundings by electrical work / mechanical work / radiation

All the appliances in the table are used for different amounts of time per day, but they each transfer 0.5 kWh of energy per day.

Calculate the average time used per day for the lamp.

Give your answer in hours.

Lasers are very intense light waves.

The diagram shows a light wave.

Which letter, A, B, C or D, shows the wavelength of the wave?

Which letter, A, B, C or D, shows the amplitude of the wave?

Which property of a wave gives the time it takes to complete one full cycle?

Tick (✓) one box.

A student uses a laser to investigate how light reflects from a mirror.

State one risk of using a laser.

The laser is directed towards the mirror at different angles of incidence and the student measures the angle of reflection.

The table shows the student’s results.

Calculate the mean angle of reflection when the angle of incidence is 40°.

The laser is now directed at the mirror so that the angle of incidence is 60°.

Predict the angle of reflection.

Explain how the data in the table supports your answer.

A laser produces a beam of red light.

The wave speed of the red light is 3.0 × 10⁸ m / s.

The wavelength of the red light is 750 × 10^–9 m.

Calculate the frequency of the red light.

Give your answer in standard form.

A bike is fitted with a device which uses the motion of the front wheel to generate electricity. The electricity generated is used to power lights and a USB charger.

The diagram below shows a simplified layout for the device on the bike.

The rotation of the wheel creates the spinning motion needed to induce a potential difference in a coil of wire.

What must be spinning near the coil of wire to induce a potential difference?

Tick (✓) one box.

The circuit diagram shows how the lights and the USB charger are connected to the device.

The switches shown are all open.

A component can be added to the circuit to measure current.

Draw the symbol for the component that measures current.

When the bike lights and USB charger are each operating at 5 V, what is the potential difference across the power supply from the device?

Complete the sentences to describe the energy transfers in the circuit.

Use words from the list.

closed current open potential difference power

When a........ flows in the circuit, energy is transferred from the

power supply to each component.

A component will get no energy if the switch in that loop is........

Draw a line of best fit on the graph.

Find the pedal speed for a potential difference of 5V.

Use your line of best fit.

A mobile phone is plugged into the USB charger.

Calculate the charge that flows through the USB charger when:

• the current through the USB charger is 0.5 A.

• the phone is charged for 1200 s.

Use the equation: charge = current × time

What quantity needs to be multiplied by potential difference to find the power of the USB charger?

Tick (✓) one box.

Calculate the energy output of the USB charger.

• The charge passing through the USB charger is 2000 C.

• The potential difference across the USB charger is 5 V.

Use the Equation Sheet.

Give your answer in kJ.

A bag containing fluid is used in a remote-control fish.

The bag is stretchy so its size can change.

The fluid in the bag changes between liquid and gas to control the depth of the fish in the water.

The diagram shows nine particles inside the bag when the fluid is a liquid.

The bag becomes larger when the fluid becomes a gas.

Complete the diagram below to show how the same particles are arranged in the bag when the fluid is a gas.

Calculate the density of the fluid in the bag when it is a liquid.

• There is 0.45 g of fluid in each bag.

• The volume of the fluid when liquid is 0.3 cm³.

Use the Equation Sheet.

Density =........ g / cm³

When the fluid in the bag is a gas it has a volume of 4 cm³. (iii)

Explain why the fluid has a higher density as a liquid than as a gas.

You can include a calculation in your answer.

Calculate the energy needed to change the state of the fluid from liquid into gas.

• The mass of the fluid is 0.00045 kg.

• The specific latent heat is 200 000 J / kg.

Use the Equation Sheet.

Which statements about the fluid in the bag are true and which are false ?

Tick (✓) one box in each row.

Marie Curie discovered the radioactive element, radium. Her notebook from 1920 is still radioactive today.

The graph shows the change in activity of the radium on the notebook over the next 4500 years.

Why does the activity of a radioactive source decrease?

Tick (✓) one box.

What will the activity of the radium on the notebook be 2500 years from now?

Use the graph.

Find the half-life of radium.

Use the graph.

Explain why the statement below is not correct.

The radium on the notebook will be much less radioactive in 100 years’ time.

Touching the notebook is a risk.

Complete the sentence about this risk.

Use words from the list.

contaminated irradiated neutral undecayed

If the........ radium nuclei get into broken skin on a person’s hand, the

person will become........

The radium emits alpha and gamma radiation.

Suggest one safety precaution that can be taken for each type of radiation.

Safety precaution to lower the risk from alpha radiation:........

Safety precaution to lower the risk from gamma radiation:........

Satellites contain thrusters which change the height of a satellite orbiting the Earth.

What force keeps satellites orbiting the Earth?

The thruster ejects gas to change the speed of the satellite.

Newton’s third law explains the interaction between the ejected gas and the satellite.

Select Newton’s third law.

Tick (✓) one box.

Explain how the thruster ejecting a gas causes the satellite to change speed.

Use ideas about forces.

The distance travelled from A to C is 5000 m.

Find the distance from A to B.

Use:

• Fig. 8.1

• a ruler.

When the boat leaves A, the time is 09:23. When the boat reaches B, the time is 09:53.

Calculate the average speed of the boat for its journey from A to B.

Use the Equation Sheet.

Give your answer in m / s.

Average speed =........ m / s

Fig. 8.2 shows the speed–time graph for the boat for a short period.

Calculate the acceleration of the boat.

Use Fig. 8.2.

Acceleration =........ m / s²

The boat has a force acting on it from the wind.

Which of these is a typical value for the speed of wind?

Tick (✓) one box.

In the 1930s, scientists experimented with elements and split their nuclei.

Complete the sentences about splitting the nucleus.

Use words from the list.

fission fusion negative

power stable unstable

The nuclei of certain elements can be split into two smaller nuclei because they

are........

The process is called nuclear........

Suggest why Enrico Fermi’s hypothesis was believed in 1934.

Explain why, by 1940, more scientists had confidence in the theory that nuclei can be split.

Use information from the table to support your answer.

When uranium nuclei split, neutrons are released and a chain reaction happens.

Which statement correctly explains how a chain reaction happens?

Tick (✓) one box.

Which two statements describe how the energy is released when uranium nuclei split?

Tick (✓) two boxes.