OCR GCSE Combined Science B (21st Century) Paper 3 June 2024 question paper

The table shows some of the main groupings of the electromagnetic spectrum.

Complete the table.

Which statement correctly compares a radio wave and an X-ray?

Tick (✓) one box.

X-rays can remove electrons from atoms.

What is the removal of an outer electron from an atom called?

Tick (✓) one box.

The diagram shows some ocean waves.

Choose from A, B, C, or D.

The speed of some water waves on the ocean is 2.8 m / s. The frequency of the waves is 0.35 Hz.

Calculate the wavelength of the waves.

A student wants to know how different energy resources are used to generate electricity.

Complete the table about the generation of electricity.

Use words from the list:

Coal Solar radiation Wind

Wind and solar radiation are examples of renewable energy resources. Coal is a non-renewable energy resource.

State one other renewable energy resource and one other non-renewable energy resource.

Renewable energy resource:........

Non-renewable energy resource:........

Complete the sentences about global warming.

One of the main greenhouse gases in the Earth’s atmosphere is carbon dioxide / nitrogen / oxygen

The amounts of greenhouse gases in the atmosphere have been increasing over the past two hundred years mostly because of the increasing use of biofuels / fossil fuels / nuclear fuels

A hydrotherapy pool contains hot water. It is used to help people with some medical conditions.

A water heater in a pool has a power of 2300 W. It is switched on for 6 hours.

Calculate the total energy transferred to the pool in 6 hours.

Give your answer in kWh.

Use the Equation Sheet.

Suggest one reason for using the kilowatt-hour rather than the joule on electricity bills.

The pool contains 1250 kg of water. A water heater inside the pool heats up the water. Over 6 hours the temperature of the water rises from 32 °C to 36 °C.

Calculate the increase in the internal energy store of the water over 6 hours.

Use the Equation Sheet.

Specific heat capacity of water = 4200 J / kg / °C

On another day, the total energy transferred by the water heater is 15 kWh and the increase in internal energy of the water is 10.8 kWh.

Calculate the efficiency of the water heater.

Use the equation:

When the pool is not being used the water cools down.

Suggest how the cooling effect can be reduced.

A student does an experiment to compare three materials as thermal insulators.

The diagram shows the equipment used.

This is the method:

• Fill the space between the metal containers with the insulating material.

• Pour 100 cm³ boiling water into the inner container and place a lid on the container.

• Place a thermometer in the water.

• Start a stopwatch when the temperature drops to 80 °C.

• After 5 minutes measure the final temperature of the water.

• Repeat the experiment with different insulating materials.

List three factors that need to be controlled in this experiment.

The table shows the results of the experiment.

Which material is the best thermal insulator?

Explain your answer.

Calculate the rate of change of temperature for straw, in degrees celsius per second.

Use the data from the table and the equation:

Give your answer to 2 significant figures.

Rate of change of temperature for straw =........ °C / s

A physical quantity is something that can be measured and given a value.

Complete the table by writing in the unit for each physical quantity.

A physical quantity can be a vector quantity or a scalar quantity.

Complete the table.

Tick (✓) one box in each row.

A car travels at a constant speed of 13.4 m / s.

Calculate the distance travelled by the car in 15 seconds. Use the equation: average speed =

Fig. 7.1 shows some equipment used to find the density of a liquid.

Calculate the mass of the 60 cm³ of liquid. (i)

Use Fig. 7.1.

Calculate the density of the liquid. Use the equation: density =

Density =........ g / cm³

Fig. 7.2 shows a fixed mass of gas trapped in a cylinder by a piston. The piston can be moved up and down.

Complete the sentence to explain what happens to the density of the trapped gas when the piston is moved downwards.

The density of the gas decreases / increases / stays the same

because........

The piston is then fixed in place so that it cannot move.

The trapped gas is heated. This causes the pressure inside the cylinder to increase.

Explain why the gas molecules apply a larger pressure on the cylinder when the trapped gas is heated.

A student investigates how the length of a spring changes when masses are added to it, using the equipment in Fig. 8.1.

The results are shown in the table.

Calculate the extension of the spring when the mass is 400 g.

Write your answer in the table.

Calculate the spring constant when the mass is 300 g.

Use the table and the equation: weight = spring constant × extension

Give your answer to 2 decimal places.

Spring constant =........ N / cm

The graph shows the results of the experiment.

Describe the relationship between the weight and the extension of the spring.

Use data from the graph or the table to support your answer.

The energy stored in a stretched spring is given by the equation: Energy stored in a stretched spring = × spring constant × (extension)²

What happens to the energy stored in a stretched spring when the extension is doubled?

The energy stored increases by:

less than two times / two times / more than two times.

Explain your answer to (d)(i).

Electric circuits are represented by symbols.

Draw lines to connect each symbol to its name and its use.

The graph shows how the current through a filament lamp varies with the potential difference across it.

Describe how the current in the filament lamp changes as the potential difference across it increases from 0 V to 4 V.

Calculate the resistance of the filament lamp when the potential difference across it is 2.2 V.

Use the graph and the Equation Sheet.

The diagram shows part of the circuit that a student uses to obtain these results.

Complete the circuit diagram by adding a variable resistor, voltmeter and an ammeter to the circuit.

10* The diagram shows a pumped storage system.

Electricity is used to pump water from the lower reservoir to the upper reservoir. When the water flows back down, its kinetic energy store is used to generate electricity.

Describe the benefits and risks of replacing fossil fuel power stations with wind farms and solar panels and explain how pumped storage systems can help to reduce the risks.

A student is investigating the motion of a trolley travelling down a ramp, using the equipment shown in Fig. 11.1.

Fig. 11.1

Describe how the student can use a metre ruler and a stopwatch to find out the average speed of the trolley down the ramp. Use the idea that average speed =

Fig. 11.2 shows how far the trolley travels down the ramp in a given time.

Fig. 11.2

Explain how Fig. 11.2 shows that the trolley accelerates down the slope.

Draw a tangent on Fig. 11.2 at Time = 5.0 s and use it to calculate the gradient at this time.

Gradient =........ cm / s

The student then investigates how the size of a pulling force affects the motion of the trolley down the ramp.

Fig. 11.3 shows the equipment used.

Fig. 11.3

The pulling force on the trolley is provided by a falling weight attached to the trolley by a string.

The student measures the acceleration of the trolley when different weights are used.

Fig. 11.4 shows the student’s results.

Fig. 11.4

Calculate the resultant force acting on the trolley when the falling weight is 0.50 N.

The mass of the trolley is 0.80 kg.

Use Fig. 11.4 and the Equation Sheet.