IGCSE Physics 0625 Paper 41, Oct/Nov 2025

State the difference between the velocity of the train and its speed.

Calculate the kinetic energy stored in the moving train. kinetic energy = .........................................................

The train has a uniform deceleration of $1.2{\text{ m/s}}^2$. Calculate the constant braking force which brings the train to rest. force = .........................................................

Calculate the distance travelled by the train as it comes to rest. distance = .........................................................

Define gravitational field strength.

An object has a weight of $42\text{ N}$ at the surface of the Earth. Calculate the weight of the object at the surface of Mars. weight = .........................................................

Calculate the volume of Mars. volume = .........................................................

Fig. 2.1 shows a space buggy that is tested on Earth. The buggy is travelling at a constant speed in a straight line. The driving force on the buggy is $30\text{ N}$. Draw and label one arrow on Fig. 2.1 to show the size and direction of the resistive forces on the buggy.

Air resistance on Mars is less than air resistance on Earth. The same driving force, $30\text{ N}$, is exerted on the buggy on Mars. 1. State the effect this has on the resultant force on the buggy on Mars. ........................................................................................................................................... 2. State the relationship between resistive forces, driving force and resultant force.

Describe the energy transfer in the solar cell.

Suggest how the black coating allows the solar cell to transfer more energy.

$0.72\text{ kW}$ of light is incident on the solar cell in Fig. 3.1. The cell has an efficiency of $75\mathrm{\%}$. Calculate the output power of the cell. output power = .........................................................

State the meaning of the term kilowatt-hour (kWh).

Energy is produced by each solar cell for an average of 6 hours per day. A household uses approximately $7400\text{ kWh}$ of electrical energy per year. Calculate the number of solar cells needed to produce energy for one household. Give your answer as a whole number of solar cells. number of solar cells = .........................................................

A $12\text{ V}$, $50\text{ W}$ immersion heater is used to heat $0.15\text{ kg}$ of water in a beaker. The water is initially at a room temperature of ${20}^{\circ }\text{C}$. The specific heat capacity of water is $4200\text{ J}\mathrm{/}(\text{kg}{}^{\circ }\text{C})$. Calculate the energy supplied to raise the temperature of the water from ${20}^{\circ }\text{C}$ to ${58}^{\circ }\text{C}$. energy = .........................................................

The immersion heater is removed from the beaker. One metal rod and one plastic rod are placed in the beaker of hot water as shown in Fig. 4.1. The rods are at room temperature (${20}^{\circ }\text{C}$) before they are placed into the beaker. Describe how the temperature of point X on each rod changes after the rods are placed in the beaker. Explain your answer.

State the value of the speed of sound in air and state how the speed of sound in water differs from the speed of sound in air. speed of sound in air ........................................................ m/s speed of sound in water ...............................................................

State and explain if humans with normal hearing can hear all the sounds emitted by the dolphin. statement ................................................................. explanation ............................................................................................................................... ...................................................................................................................................................

Complete Table 5.1 to describe differences in loudness and pitch of two different dolphin sounds. Table 5.1 Frequency /kHz | amplitude | loudness | pitch 14 | large | | 8 | small | |

Complete the sentences to describe how sound is transmitted through water. Sound waves are made of vibrating .................................................. which produce compressions and rarefactions. A compression is a region of .................................................. and a rarefaction is a region of .................................................. . The sound waves travel .................................................. to the direction of the vibrations.

State two advantages of using optical fibres in high-speed data transmission compared to electrical signals sent on copper wires.

The optical fibre is made of glass with a refractive index of 1.4. Calculate the critical angle $c$. c = .........................................................

State the meaning of critical angle.

On Fig. 6.1, label the angle of incidence of the ray of light as it hits the wall of the glass fibre. Draw the continuation of the ray until it leaves the glass fibre.

${\text{S}}_1$ is closed and ${\text{S}}_2$ is open. The current in the ammeter is $0.080\text{ A}$. Calculate the resistance of ${\text{R}}_1$. resistance = .........................................................

${\text{S}}_1$ and ${\text{S}}_2$ are both closed. Determine the reading on the ammeter. Show your working. ammeter reading = .........................................................

Explain in terms of work done and potential difference why there is a larger heating effect in ${\text{R}}_3$ than in ${\text{R}}_1$.

Draw on Fig. 8.1 four complete magnetic field lines that show the pattern and direction of the magnetic field inside and outside the solenoid.

Mark a point inside the box in Fig. 8.1 where the magnetic field is strong. Label this point B. Explain how the diagram shows that the magnetic field is strong at B. explanation ........................................................................................................................

Fig. 8.2 shows a solenoid in an electric circuit for a bell. Complete the circuit in Fig. 8.2 with the symbol for a direct current (d.c.) power supply.

Explain why the soft iron arm pivots, making the striker hit the bell when the switch is closed.

Explain why the arm pivots back to its original position after the striker hits the bell.

Describe the structure of an atom of helium-4, ${}_2^4\text{He}$.

The Sun is a medium-sized star powered by nuclear fusion reactions which release energy. State what happens during nuclear fusion reactions which form helium.

State two regions of the electromagnetic spectrum by which the Sun radiates most of its energy.

Describe what happens to a star when most of the fuel in its centre has been converted to helium.

State which orbit, A or B, is the orbit of the comet. Explain your answer. orbit of comet is .................. explanation ............................................................................................................................... ...................................................................................................................................................

Describe and explain how the motion of the comet changes as it orbits the Sun.

At one position in its orbit, the comet is $6.6\times {10}^{-6}\text{ light-years}$ away from the Earth. State the meaning of light-year.

Determine the distance in metres between the comet and the Earth. distance = ......................................................m