Edexcel IGCSE Physics Physics Paper 2 June 2025 question paper 4PH1/2PR

A flour mill is a factory where flour is produced.

The photograph shows some flour moving through metal channels in the flour mill.

The flour particles can become charged as they move through the metal channels.

Explain how the flour particles can become charged.

The charged flour particles move away from each other as they fall from the end of each channel.

Complete the passage by writing a suitable word or words in each blank space.

Flour particles move away from each other because they have

_........ charges. This causes the flour particles

to exert_........ forces on each other.

The dust created by producing flour in a flour mill is dangerous because the dust is flammable. This creates a risk of an explosion.

Explain why connecting the metal channels to earth reduces the risk of an explosion in a flour mill.

Uranium‑239 is an isotope of the element uranium.

State what is meant by the term isotopes.

Uranium‑239 can be represented using the symbol

Protons are one type of particle found in the nucleus of an atom.

How many protons are in the nucleus of an atom of uranium‑239?

Give the name of the other particle found in the nucleus of an atom of uranium‑239.

Uranium‑239 is radioactive and decays by beta emission.

Uranium‑239 has a half‑life of 23 minutes.

A sample of uranium‑239 has an initial mass of 60 g.

Calculate the mass of uranium‑239 remaining after 46 minutes.

When uranium‑239 undergoes beta decay, an isotope of the element neptunium, Np, is produced.

Which of these is the correct symbol for the neptunium nucleus produced in the beta decay of uranium‑239?

The photograph shows the tidal power station across the estuary of the river Rance in France.

The diagram shows a simplified view of the tidal power station.

At high tide, water is trapped behind the tidal barrier.

At low tide, the trapped water is released through the turbine shaft. This causes a turbine to spin, which generates electricity.

Give two advantages of generating electricity using tidal power.

Give two disadvantages of generating electricity using tidal power.

At low tide, water flows through the turbine shaft.

As the height of the trapped water in the river decreases, water falls through a height of 8.0 m to reach the turbine shaft.

Calculate the energy transferred from the gravitational store of the water when 1.0 kg of water flows through the turbine shaft.

Use the formula

change in gravitational potential energy = mass × g × height

The tidal power station has a maximum power output of 240 000 kW when water falls through a height of 8.0 m.

Calculate the mass of water flowing through the turbine shaft in 1 second when the power station is operating at maximum power.

Assume the power station is 100% efficient.

This question is about transformers.

Describe the structure of a step‑up transformer.

You may draw a diagram to help your answer.

A step‑up transformer has an input voltage of 230 V and an input current of 4.5 A.

The output current of the transformer is 0.21 A.

State the formula linking input power and output power for a transformer that is 100% efficient.

Calculate the output voltage of the transformer.

A tennis ball is dropped from a height above the ground.

Diagram 1 shows the tennis ball at the instant it is released.

Diagram 1

On diagram 1, draw a labelled arrow to show the force acting on the tennis ball at the instant it is released.

Diagram 2 shows the tennis ball at the instant it hits the ground.

Diagram 2

Just before hitting the ground, the tennis ball is moving downwards at a velocity of 2.5 m/s.

Just after hitting the ground, the tennis ball is moving upwards at a speed of 1.9 m/s.

The mass of the tennis ball is 0.057 kg.

Calculate the change in momentum of the tennis ball when it hits the ground.

Give the unit.

The ball is in contact with the ground for a time of 6.0 ms.

Calculate the force exerted on the ball by the ground.

Give the direction of this force.

The coefficient of restitution can be used to determine how high a ball will bounce. The higher the value of the coefficient of restitution, the higher the ball will bounce.

Diagram 3 shows a ball being dropped from a height (h₁) above the ground.

The ball hits the ground and bounces.

At the top of its bounce, the ball reaches a height (h₂) above the ground.

The coefficient of restitution can be determined using the formula

A student decides to do an investigation to compare the coefficient of restitution for different types of ball.

Design a method for the student’s investigation.

Your answer should include details of

• the variables in the investigation

• how to obtain accurate measurements

• how to obtain reliable results

You may add to diagram 3 or draw an additional diagram to help your answer.

This question is about cosmic microwave background radiation (CMBR) and the Big Bang.

CMBR has a mean frequency of 1.6 × 10¹¹Hz.

State the formula linking wave speed, frequency and wavelength.

Show that the mean wavelength of CMBR is about 2 mm.

[speed of light = 3.0 × 10⁸m/s]

CMBR was first released after the Big Bang.

When CMBR was first released it had a wavelength of about 9 × 10^–5mm, but now it has a wavelength of about 2 mm.

Using this information, explain how CMBR supports the Big Bang theory.

Explain how the cosmological red‑shift of galaxies also supports the Big Bang theory.

The photograph shows a cup that is designed to keep a drink hot.

The inside surface of the cup is shiny and silver‑coloured.

Explain how the shiny silver‑coloured surface helps to keep a drink hot.

Explain why a drink in the cup will stay hot for longer when the lid is placed on the cup.

A student investigates how the temperature of a drink in the cup varies with time.

This is the student’s method.

• pour some hot water into the cup and place the lid on the cup

• wait for the water to cool to 80C and then start a stopwatch

• measure the temperature of the water in the cup every 10 minutes

The graph shows the student’s results.

On the graph, draw a tangent to the curve when the temperature is 40C.

Calculate the gradient of the tangent to find the rate of temperature change of the water when the temperature is 40C.

Give your answer in C / minute.

rate of temperature change =_........ °C / minute

The student is working in a laboratory with a room temperature of 20C.

Draw a line on the graph to show how the temperature of the water in the cup would change if there was no lid on the cup.

A high‑frequency sound wave is detected by a microphone and displayed on an oscilloscope.

The diagram shows the oscilloscope screen when the sound wave is detected. It also shows the oscilloscope settings.

Give the maximum frequency of sound that can be heard by humans.

Determine if the sound wave displayed on the oscilloscope could be heard by humans.

A student changes the settings of the oscilloscope to alter the displayed wave in these two ways.

• increase the amplitude of the wave

• only display one time period of the wave on the screen

The table shows some possible settings for the oscilloscope.

Which row of the table gives the student’s new oscilloscope settings?