4PH1/2P — November 2025 (Edexcel IGCSE Physics): Past Paper

The diagram shows the apparatus used to investigate electric charge. The equipment is viewed from above.

• ball 1 and ball 2 have a positive charge
• ball 1 is fixed in place
• ball 2 is attached to a rod that can rotate about point P
• ball 2 does not move ball 1 force from spring spring rod ball 2 P 4.2 cm F

State, in terms of charged particles, how the balls have become positively charged.

Ball 1 exerts a force, F, of 0.57 N on ball 2.

State the value of the force exerted on ball 1 from ball 2. force = N

Calculate the moment on the rod from force F about point P. moment = N cm

State the magnitude of the moment about point P due to the force from the spring. magnitude of moment = N cm

Draw an arrow on the diagram to show the direction of the force that the rod exerts on the spring.

This question is about gravitational field strength.

The table shows gravitational field strengths at the surfaces of four different planets. The planets have the same mass but different diameters. Diameter Gravitational field in km strength in N/kg 13 000 9.8 18 000 5.1 21 000 3.8 24 000 2.9 Give a reason why a scatter graph is the correct way to display this data, rather than a bar chart.

No printed figure accompanies this part — in the paper you would draw the diagram (or label the apparatus) in the answer space provided.

A student claims that the relationship between the gravitational field strength and the diameter of a planet is given by this formula. gravitational field strength × (diameter)² = constant Using data from the table, evaluate the student’s claim.

The diameter of a planet affects the gravitational field strength at the surface of the planet. Which of these is also a factor that affects gravitational field strength?

The diagram shows some of the parts of a hydroelectric power station. electricity transformer spillway generator powerhouse dam turbine water discharge water flow (Source: © Radzas2008/Shutterstock)

Water enters the turbine with a momentum of 120 000 kg m/s.

State the formula linking momentum, mass and velocity.

A mass of 14 000 kg of water enters the turbine. Calculate the velocity of the water as it enters the turbine. velocity = m/s

The 14 000 kg of water leaves the turbine. This water has a momentum of 63 000 kg m/s after it leaves the turbine. The turbine exerts a force of 6100 N on the water. Calculate the time taken for the water to pass through the turbine. time = s

As the water passes through the turbine, energy is lost from the water’s kinetic energy store. Explain what happens to the energy lost from the water’s kinetic energy store.

Hydroelectric power is an example of a renewable resource for the generation of electricity. Give two examples of non-renewable resources for the generation of electricity. 1 2

This question is about sound waves.

Describe an investigation to measure the frequency of a sound wave with an oscilloscope. You may draw a diagram to help your answer.

The diagram shows an oscilloscope screen. Oscilloscope settings: x direction: 1 square = 0.5 ms y direction: 1 square = 0.5 V

Estimate the period, in ms, of the wave. period = ms

Calculate the frequency of the wave. frequency = Hz

The diagram shows a cross‑section of a solenoid. Key current into paper current out of paper

Draw one field line on the diagram to show the direction of the magnetic field.

Use the field line to determine which end of the solenoid is the north pole and label this on the diagram.

A transformer consists of two solenoids and an iron core. This is the label on the transformer. Number of turns on primary coil: 180 Number of turns on secondary coil: 345 Output voltage: 230 V Output power = 320 W

State the formula linking input (primary) voltage, output (secondary) voltage and the turns ratio.

Calculate the input voltage of this transformer. input voltage = V

Give the name of this type of transformer.

When the transformer is in use, there is a current in the primary coil and in the secondary coil. State the type of current in the coils of the transformer.

Galaxies A, B and C are different distances from the Earth. Galaxy A is moving away from the Earth with a velocity of 1.7 × 10⁴ km/s.

The reference wavelength for light arriving at the Earth from galaxy A is 506 nm. Calculate the observed wavelength for the light arriving from galaxy A. [speed of light = 3.0 × 10⁵ km/s] wavelength = nm

Galaxy B is twice as far away from the Earth as galaxy A is from the Earth. Galaxy C is four times as far away from the Earth as galaxy A is from the Earth. Explain how the velocities of galaxies B and C are different.

The universe started with an event called the Big Bang. Explain how evidence from cosmic microwave background radiation shows how the temperature of the universe has changed since the Big Bang.

A student investigates how the temperature of a metal block varies with time as it is heated. The student measures the temperature of the block at 5-minute intervals for a total of 30 minutes. The graph shows the student’s results. 450 Temperature in C 0 5 10 15 20 25 30 Time in minutes

Give the name of a piece of equipment that the student could use to measure the time during the investigation.

Which of these is the dependent variable in this investigation?

The energy supplied to the block is 440 000 J. Calculate the mass of the metal block when the temperature of the block increases from 45 °C to its melting point of 450 °C. [for the metal, specific heat capacity = 910 J / kg °C] mass = kg

The metal block melts and then the liquid metal boils to become a gas. Describe the motion of the particles when the metal is a gas.

Suggest two changes to the graph if the student had used a different metal in their investigation. 1 2

The photograph shows a nuclear power station. (Source: © Julius Fekete/Shutterstock) A chain reaction releases energy inside the power station.

Explain how the fission of U-235 can set up a chain reaction.

Explain how nuclear fusion is different from radioactive decay.

An isotope of hydrogen is used as a fuel for nuclear fusion. The nuclear equation shows how this isotope of hydrogen can be manufactured. Complete the equation by giving the missing information. n + Li → 2α 1 6 4 H + 3 1

Explain why nuclear fusion can only happen at high temperatures and pressures.

Which of these is the time taken for the number of undecayed nuclei in a radioactive isotope to halve?

This isotope of hydrogen is radioactive and has a half‑life of 12 years. A sample of the isotope has an activity of 72 kBq. Calculate the activity of the isotope in the sample after 60 years. activity = kBq