4PH1/2P — June 2022 (Edexcel IGCSE Physics): Past Paper

A student uses a watt-meter to measure the power of electrically‑operated appliances.

State what is meant by the term power.

The student measures the mean power output (in watts) for six different appliances. Diagram 1 shows their results. Toaster = 1068 W Kettle = 2025 W Laptop = 47 W Electric drill = 713 W Television = 59 W Hair dryer = 1511 W Diagram 1 Draw a results table for the student’s results.

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

The student measures the power output for a different appliance. Diagram 2 shows their raw data. 199 W 202 W 201 W 213 W 200 W 201 W Diagram 2

The student identifies an anomalous result in their data. Draw a circle around the anomalous result.

Calculate the mean power output for this appliance. Give your answer to three significant figures. mean power output = W

This question is about momentum.

Which of these is the correct unit for momentum?

The diagram shows an object before and after an explosion. The object breaks into two parts, P and Q. The parts move away from each other in opposite directions. object stationary v P Q 3.7 m / s 4.8 kg 2.9 kg 1.9 kg Before After

State what is meant by the principle of conservation of momentum.

Calculate the magnitude of the velocity of part P after the explosion. velocity = m / s

A child drops an egg from a height of 10 cm and the egg lands on the floor. Explain why the egg is less likely to break if the floor is covered with a thick carpet than if the floor were covered in hard tiles.

Mobile phone charger X contains a transformer and is used to charge the phone’s battery. Diagram 1 shows the information on charger X. Input voltage = 230 V Output voltage = 5.0 V Output current = 1.2 A Diagram 1

The power of the charger can be calculated using the formula power = current × voltage Calculate the output power of charger X. output power = W

Calculate the input current to charger X. Assume that charger X is 100% efficient. input current = A

Charger X transfers a charge of 10 500 C to the mobile phone battery.

State the formula linking charge, current and time.

Calculate the time in minutes to transfer a charge of 10 500 C to the battery. time = minutes

Charger Y can also be used to charge the mobile phone battery. Diagram 2 shows the information label for charger Y. Input voltage = 230 V Output voltage = 5.0 V Output current = 2.1 A Diagram 2 Explain how the time taken to transfer the same amount of charge to the mobile phone battery will be affected when charger Y is used instead of charger X.

Both chargers contain step-down transformers. Explain how a step-down transformer works. You may include a diagram to support your answer.

Sound waves with a frequency above the range of human hearing are known as ultrasound.

State the frequency range for human hearing.

The frequency of ultrasound waves can be determined using an oscilloscope.

Give the name of the piece of apparatus that could be connected to the oscilloscope to detect the ultrasound waves.

The time period of the ultrasound waves must be measured to determine their frequency. Describe how the oscilloscope is used to measure the time period of the ultrasound waves.

The diagram shows the oscilloscope screen when an ultrasound wave is detected. The oscilloscope settings are also shown. oscilloscope settings: y direction: 1 square = 2 V x direction: 1 square = 5 × 10−6 s

Determine the time period of the ultrasound waves. time period = s

Calculate the frequency of the ultrasound waves. frequency = Hz

The table gives some statements about different parts of a nuclear reactor. Place ticks (✓) in the boxes to show which statements are about the moderator and which statements are about a control rod in a nuclear reactor. Moderator Control rod absorbs excess neutrons can be made of boron can be made of water or graphite is lowered into or raised from the reactor core to adjust the rate of reaction reduces the speed of neutrons so they are more likely to cause fission

Describe the role of shielding around a nuclear reactor.

A uranium fuel rod is made from fuel pellets that contain uranium‑235 and uranium‑238. Only uranium‑235 undergoes nuclear fission in the reactor core. Energy is released when the uranium‑235 nuclei undergo fission. The box gives some data about a typical uranium fuel pellet. Total mass of uranium in fuel pellet 0.0088 kg Percentage (by mass) of uranium‑235 in fuel pellet 3.0 % Mass of uranium‑235 atom 3.90 × 10−25 kg Total energy released from fuel pellet due to fission 2.17 × 1010 J

Calculate the number of uranium‑235 atoms in the fuel pellet. number of uranium‑235 atoms =

Calculate the energy released when the nucleus of a single atom of uranium‑235 undergoes fission. energy released = J

The universe began with an event known as the Big Bang.

Describe how the size and temperature of the universe have changed since the Big Bang.

Discuss two pieces of evidence that support the Big Bang theory.

This question is about specific heat capacity.

State what is meant by the term specific heat capacity.

A student uses this method to measure the specific heat capacity of water. • place an aluminium block of known mass in an oven at a temperature of 220 °C • place water of known mass in a container at a temperature of 20 °C • leave the aluminium block in the oven for 10 minutes • remove the aluminium block from the oven and place the block in the water • measure the maximum temperature of the water after it has been heated by the aluminium block The student uses their data to calculate the specific heat capacity of water. Give two ways that they could improve their method to increase the accuracy of their value of specific heat capacity. 1 2

The box shows the student’s data. Mass of aluminium block = 1.6 kg Mass of water = 2.3 kg Initial temperature of water = 20 °C Maximum temperature of water = 38 °C

When the water reaches its maximum temperature, the water and aluminium block are in thermal equilibrium. State the temperature of the aluminium block as it reaches thermal equilibrium with the water. temperature of aluminium = °C

Calculate the temperature change of the water when it has been heated to its maximum temperature. temperature change of water = °C

The water gains 190 000 J of energy in its thermal store as it is heated to its maximum temperature. Calculate the specific heat capacity of water. specific heat capacity of water = J / kg °C

After finishing the experiment, the student removes the aluminium block and places the container of water into a freezer. The water loses energy at a constant rate and cools from 38 °C to –20 °C. The water freezes and turns into ice at 0 °C. Ice has a lower specific heat capacity than water. Use the axes to sketch a temperature-time graph from when the water is placed in the freezer until it reaches its lowest temperature. No calculations are required. Temperature in °C Time −10 −20