4PH1/2PR — June 2019 (Edexcel IGCSE Physics): Past Paper

The diagram shows a fossil fuel power station. Five stages of electricity generation and transmission are shown. steam water furnace and boiler condenser turbines generator transformer

The power station burns a fossil fuel in the furnace. Give an example of a fossil fuel.

Which stage of the power station transfers energy from a chemical store to a thermal store?

Which stage of the power station transfers energy electrically from a kinetic energy store?

Electricity can also be generated by solar farms. (Source: © Zoonar GmbH/Alamy) Energy is transferred from the Sun to the solar farm by radiation. The solar farm uses photovoltaic cells to transfer this energy electrically. Discuss the advantages and disadvantages of generating electricity using solar farms.

This question is about sound waves.

Sound is an example of a type of wave. State the name of this type of wave.

The speed of sound in liquids is greater than the speed of sound in gases.

Describe the arrangement of particles in liquids and in gases. You may use diagrams to help your answer.

Suggest why the speed of sound in liquids is greater than the speed of sound in gases.

A buzzer is an electrical device that produces sound. The frequency of sound produced by the buzzer is 1400 Hz.

State the formula linking speed, frequency and wavelength of a wave.

Sound travels at a speed of 340 m/s in air. Calculate the wavelength of the sound wave from the buzzer. wavelength = m

Two students use this method to investigate sound from a moving source. Student A connects a piece of string to the buzzer. She spins round so that the buzzer moves in a horizontal circular path. ● she spins round at a slow speed ● she then spins round at a high speed Student B stands several metres away from student A. student A student B buzzer The sound heard by student A is different to the sound heard by student B. Discuss the differences in the sounds heard by student A and student B.

A student charges a plastic rod by rubbing it with a cloth. The rod becomes negatively charged.

Which statement explains how the rod becomes negatively charged?

Describe how the student could demonstrate that the rod is charged.

The student has several other rods made from different kinds of plastic. Some rods can be charged positively and some can be charged negatively. Describe an experiment to show that different rods have different types of charge. You may draw a diagram to help your answer.

A Hertzsprung‑Russell diagram shows how different astronomical objects may be classified according to their colour and absolute magnitude. –5 red giants main sequence Absolute +5 magnitude +10 white dwarfs +15 blue white yellow red Colour The diagram shows three stages of evolution for stars of similar mass to the Sun. Describe the evolution of stars of similar mass to the Sun. You should refer to the temperature and brightness of the stars in your answer.

Stearic acid is a solid at room temperature and melts at a temperature of 69 °C. A student investigates the specific heat capacity of solid stearic acid. He heats a sample of stearic acid from room temperature using an electrical heater and measures its temperature using a data logger and temperature sensor. The graph shows his results. Temperature in °C 40 0 100 200 300 400 500 Time in s

The student starts heating the stearic acid at 130 seconds.

Determine the time it takes to heat the stearic acid until it reaches its melting point. time = s

The stearic acid gains 39 kJ of energy during the time it is heated to its melting point. Calculate the mean (average) power of the heater. Give a unit with your answer. [assume no energy lost to surroundings] mean power = unit

The mass of stearic acid used in the investigation is 0.45 kg. The stearic acid gains 39 kJ of energy when it is heated to its melting point. Calculate the specific heat capacity of stearic acid. You should use data from the graph in your calculation. specific heat capacity = J/kg °C

A student investigates transformers.

The diagram shows a typical transformer. primary coil secondary coil core State the name given to this type of transformer.

The student investigates the effect of changing the number of turns in the secondary coil. This is his method.

• apply a constant maximum voltage to a primary coil with 1200 turns
• use a secondary coil with 100 turns
• measure the output voltage of the transformer
• replace the secondary coil with one that has 200 turns
• measure the output voltage again The student repeats this method using different numbers of turns in the secondary coil.

Suggest how the student could improve the reliability of his investigation.

These are the student’s results. number of turns = 100, number of turns = 400, output voltage = 1.3 V output voltage = 5.0 V number of turns = 200, number of turns = 500, output voltage = 2.5 V output voltage = 6.3 V number of turns = 300, number of turns = 600, output voltage = 3.8 V output voltage = 7.5 V Draw a table of these results.

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

Suggest how the student could improve the precision of his voltage measurement.

The student plots this graph to show the results of his investigation. 8.0 6.0 Output voltage in V 4.0 2.0 0.0 0 100 200 300 400 500 600 Number of turns on secondary coil

The student plots one of his results incorrectly. Draw a circle around the incorrectly plotted result on the graph.

Draw the line of best fit.

Describe the relationship shown by the graph.

The primary coil has 1200 turns. Using the student’s data, calculate the primary voltage used in his investigation. primary voltage = V

A game is played on a table with balls of different colours.

The diagram shows the white ball moving across a flat surface. v = 5.2 m/s white ball

State the formula linking momentum, mass and velocity.

The white ball has a mass of 170 g. Calculate the momentum of the white ball. momentum = kg m/s

The white ball collides with a stationary black ball. v = 5.2 m/s v v = 5.0 m/s white ball black ball white ball black ball before collision after collision

The black ball has a mass of 160 g. After the collision, the black ball moves away from the white ball with a velocity of 5.0 m/s. Calculate the velocity of the white ball after the collision. velocity of white ball = m/s

During the collision, the white ball exerts a force of 80 N on the black ball. The direction of this force is to the right. State the magnitude and direction of the force the black ball exerts on the white ball during the collision. magnitude of force = N direction of force =

The photograph shows a device that can be used to ignite small pieces of combustible material. The device consists of a cylinder containing trapped air and a piston. piston cylinder combustible material before pushing piston after pushing piston A small piece of combustible material is placed at the bottom of the cylinder. When the piston is pushed quickly into the cylinder, the trapped air is compressed and heats up. This increase in temperature is enough to ignite the combustible material.

The piston is quickly pushed down a distance of 145 mm. The average force exerted on the piston is 4.2 N.

State the formula linking work done, force and distance moved in the direction of the force.

Calculate the work done on the trapped air when the piston is quickly pushed down. work done = J

State the maximum amount of energy that could be transferred to the trapped air. energy transferred = J

Using ideas about molecules, explain why the trapped air heats up.

Suggest why the trapped air does not reach a high enough temperature to ignite the combustible material if the piston is slowly pushed into the cylinder.