4PH1/1P — June 2023 (Edexcel IGCSE Physics): Past Paper

This is a question about radioactivity.

Which of these is the unit of activity?

Which of these is the correct description of the term half-life?

A teacher demonstrates how the activity of a radioactive sample changes with time.

The box gives the names of different pieces of equipment. ruler stopwatch balance newton meter protractor GM tube voltmeter ammeter Complete the sentences using words from the box. The teacher measures time with a The teacher measures the count rate with a and a counter.

The graph shows the teacher’s results. Count rate in counts / s 0 10 20 30 40 50 Time in s Draw a circle around the anomalous result.

Use the graph to determine the half-life of the radioactive sample. half-life = s

Give a reason why the teacher should not expect the data points to lie exactly on the curve of best fit.

A student investigates how the current in a filament lamp changes when the voltage across the lamp is varied.

Draw a circuit diagram the student could use in their investigation.

The graph shows the student’s results. 2.5 2.0 1.5 Current in A 1.0 0.5 0.0 0 2 4 6 8 Voltage in V

Describe the relationship between current and voltage shown on the graph.

State the formula linking resistance, voltage and current.

Use the graph to determine the resistance of the filament lamp when the voltage across the lamp is 7.2 V. resistance = Ω

A family has a television set.

The television set has a low power mode called standby. When on standby, the power rating of the television set is 0.27 W. Calculate the energy transferred to the television set on standby in 12 hours. energy transferred = J

In normal use, the current in the television set is 0.31 A.

Explain how a fuse works to protect the television set if there is a fault.

Explain why a 13 A fuse is not an appropriate choice of fuse to use in the plug of this television set.

Ground-penetrating radar (GPR) uses radio waves to detect changes in material underground.

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

GPR radio waves have a frequency of 170 MHz. The speed of radio waves is 3.0 × 10⁸ m / s. Calculate the wavelength of the waves. wavelength = m

A radio wave passes through the ground and refracts at the boundary between soil and rock. The diagram shows three wavefronts of the wave before and after refraction. The wave is also reflected at the boundary between the soil and the rock. Complete the diagram to show three wavefronts after the wave has been reflected at the boundary. wavefronts soil rock

Explain why the radio waves passing through the rock have a smaller wavelength than the radio waves passing through the soil.

The drawing shows a camel and a person in a desert. (Source: © Hennadii H/Shutterstock)

Describe a method you could use to find the pressure a person exerts on the ground when standing on two feet.

The total area of contact of the camel’s feet with the ground is 1300 cm². The mass of the camel is 660 kg. Calculate the pressure this camel exerts on the ground. pressure = N / cm²

The photograph shows an x-ray image of a person’s knee. The person has had part of their knee replaced. (Source: © edwardolive/Shutterstock)

X-rays are part of the electromagnetic spectrum. All electromagnetic waves are transverse waves and transfer energy.

State another property that all electromagnetic waves have in common.

State a harmful effect of excessive exposure to x-rays.

Describe the difference between transverse waves and longitudinal waves. You may draw a diagram to help your answer.

The diagram shows a part of the knee called the patella. The patella has been removed from a person’s knee. The patella is a small, irregularly shaped bone that is denser than water. Describe how to find the mass and the volume of the patella bone.

A scientist finds the volume and mass of a patella. The mass of the patella is 17 g. The volume of the patella is 13 cm³. Calculate the density of the patella. Give your answer to 2 significant figures. density = g / cm³

The circuit diagram shows a motor, power supply, switch and variable resistor connected in series. + – M

The switch is open and the motor is not moving. State how much energy is in the kinetic energy store of the motor. kinetic energy = J

The switch is closed. The motor takes 0.42 seconds to reach its maximum speed of rotation. The mean current in the motor is 3.9 A. The voltage across the motor is 7.1 V. Show that the work done on the motor during the 0.42 seconds is about 12 J. work done = J

Complete the Sankey diagram for the electric motor during the 0.42 seconds by giving the missing information. energy transferred to motor kinetic energy store of motor from battery J 12 J store of surroundings 2J

Use the Sankey diagram to calculate the efficiency of the process of bringing the motor to its maximum speed of rotation. efficiency = %

In some countries, snow can fall and collect on the ground. Diagram 1 shows that after the snow has fallen, the sky can be clear, leaving the snow directly exposed to the Sun. Sun snow ground Diagram 1

Explain why the white snow will take a long time to melt, even though directly exposed to the Sun.

Diagram 2 shows a different piece of ground that has a metal drain cover. If the snow lands on metal, the snow takes a shorter time to melt. Sun snow metal drain cover ground Diagram 2 Explain why the snow melts in a shorter time on the metal drain cover.

Explain how a convection current above the snow increases the time taken for the snow to melt.

A manometer is a device that can be used to measure the pressure difference between gas from a gas tap and the atmosphere. When a gas tap is connected to the manometer, the liquid in the manometer moves due to the additional pressure of the gas. gas from manometer gas tap liquid 0.094 m Before connecting gas tap After connecting gas tap

The pressure difference is linked to the difference in height of the two surfaces of the liquid by the formula pressure difference = density × g × height difference The height difference between the two surfaces is 0.094 m. Calculate the pressure difference between the gas from the gas tap and the atmosphere. [for liquid, density = 14 000 kg / m³ ] pressure difference = Pa

The graph shows how the velocity of the surface of the liquid changes with time from when the gas tap is opened to when the water level stops moving. Velocity in cm / s 0 0.05 0.10 0.15 0.20 0.25 Time in s

Use the graph to show that the distance travelled by the surface of the liquid is 4.7 cm.

Calculate the acceleration of the surface of the liquid. acceleration = cm / s²

Explain how the gas pressure changes if the temperature of the gas increases. You should use ideas about particles in your answer.

A student investigates how the time taken for a ball to roll down a slope changes with the distance from the bottom of the slope. This is the student’s method.

• place a ball on the slope 10 cm from the bottom of the slope
• release the ball and start a stopwatch
• stop the stopwatch when the ball arrives at the bottom of the slope
• record the time taken for the ball to roll down the slope
• repeat for different distances from the bottom of the slope

Complete the table by placing a tick (ü) to show which variables are the independent, dependent and control variables in this investigation. Independent Dependent Control Surface of slope Angle of slope Distance travelled Time taken

The table shows the student’s results. Distance travelled in cm Time taken in s 10 0.41 20 0.58 30 0.71 40 0.82 50 0.91

Plot the student’s data on the grid.

Draw a best fit curve. Distance in cm 0 0.2 0.4 0.6 0.8 1.0 Time in s

The student concludes that the results obey this relationship distance ÷ (time²) = constant Use the student’s data to deduce whether the student’s results support this conclusion.

Diagram 1 shows a light-emitting diode (LED) and a resistor in series with a cell and an ammeter. 1.5 V A 0.63 V 95 Ω Diagram 1

The voltage across the LED is 0.63 V. Calculate the current in the circuit. Give your answer in milliamps. current = mA

Diagram 2 shows a second LED and an extra resistor connected in parallel with the cell. 1.5 V A Diagram 2 The resistor and the LED are the same as the components used in diagram 1. The two resistors are identical and the two LEDs are identical. Explain how the ammeter reading will change.

A device called a metal detector can be used to find metal buried underground. transmitter coil receiver coil (Source: © mArt88/Shutterstock) The metal detector has two circuits, each containing a coil of copper wire. Diagram 1 shows the circuit for the transmitter coil. electronics transmitter coil Diagram 1

Suggest why there is a magnetic field around the transmitter coil.

The cell supplies direct current (d.c.). The electronics in diagram 1 change the direct current into alternating current (a.c.) in the coil.

Describe the difference between direct current (d.c.) and alternating current (a.c.).

Alternating current is supplied to the transmitter coil. Diagram 2 shows a gold ring in the soil below the metal detector. metal detector air soil ring Diagram 2 Explain why there is an alternating current in the gold ring.

Diagram 3 shows the circuit for the receiver coil. receiver coil loudspeaker Diagram 3 As a result of the alternating current in the gold ring, there is an alternating current in the receiving coil. Explain how an alternating current in the receiving coil causes a sound to be emitted from the loudspeaker.