4PH1/1PR — January 2022 (Edexcel IGCSE Physics): Past Paper

Bismuth‑207 is a gamma emitter and is represented by the symbol 207 83 Bi How many neutrons are in the nucleus of an atom of bismuth‑207?

Which of these gives the best description of gamma radiation?

A technician uses this method to investigate the penetration power of gamma radiation. • place a gamma emitting source at a fixed distance from a radiation detector • measure the count using the detector, for a period of one minute • place a thin sheet of lead between the source and the detector • measure the new count using the detector, for a period of one minute • increase the number of lead sheets between the source and detector and repeat this process The table gives some of the variables from the technician’s method. Complete the table by placing a tick (✓) in each row to show whether each variable is an independent, a dependent or a control variable. Independent Dependent Control Variable variable variable variable count measured using the detector distance between source and detector number of lead sheets time period for measuring the count

X‑rays and gamma rays are examples of ionising radiation.

Which of these is another example of ionising radiation?

Give one use of x‑rays and one use of gamma rays. x‑rays gamma rays

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

Calculate the wavelength of a gamma ray with a frequency of 2.8 × 10¹⁹ Hz. [speed of gamma ray = 3.0 × 10⁸ m/s] wavelength = m

X‑rays and gamma rays are electromagnetic waves. Which of these graphs is correct for waves travelling at a constant speed? frequency frequency 0 0 0 0 wavelength wavelength A B frequency frequency 0 0 0 0 wavelength wavelength C D

A student uses this apparatus to measure the force of repulsion between magnet A and magnet B. N magnet A (clamped in position) S S magnet B N plastic top plate 1.6 N balance Magnet A is clamped in a fixed position. Magnet B is resting on a balance.

Give a reason why the two magnets shown in the diagram will repel each other.

Give a reason why the top plate of the balance is not affected by the magnetic fields of the magnets.

Complete the diagram by drawing the shape and direction of the magnetic field pattern between the magnets.

In the position shown, the balance reading is 1.6 N.

Explain how the balance reading will change if magnet A is brought closer to magnet B.

Explain how the balance reading will change if the poles of magnet A are reversed but the distance between the magnets remains constant.

This question is about scalar quantities and vector quantities.

Give a similarity and a difference for scalar quantities and vector quantities. similarity difference

The box gives some physical quantities. Draw a circle around each physical quantity that is a scalar. acceleration charge force power temperature velocity weight

The diagram shows four forces acting on an object. Calculate the size and direction of the resultant force. 5N 8N 2N 5N resultant force = N direction =

The chart shows the efficiencies of different methods of generating electricity. hydroelectric (large) hydroelectric (small) oil nuclear fission wind turbine geothermal 0 10 20 30 40 50 60 70 80 90 100 Electricity generation efficiencies (%)

The chart shows that the geothermal power station has an efficiency of 15%. Explain what is meant by an efficiency of 15%.

A small hydroelectric power station has a useful energy output of 6.0 kJ. Calculate the total energy input for this power station using information from the chart. total energy input = kJ

Name a fuel used in the reactor of a nuclear power station.

These sentences describe the process of nuclear fission. Complete these sentences by writing a suitable word in each blank space. A nucleus absorbs a The nucleus formed splits because it is The nucleus splits into two smaller nuclei called nuclei and two or three The energy released is transferred into the energy store of the fission products.

This question is about stars.

Table 1 gives some information about four stars. Mass relative to Star Colour the Sun 61 Cygni A orange 0.7 Antares A red 12 Sirius B blue 1.0 Vega blue‑white 2.1 Table 1

Stars can be classified using their surface temperature. Complete Table 2 by giving the four stars in order of increasing surface temperature. Coolest Hottest Table 2

Name the star in Table 1 that does not follow a similar evolutionary path to the Sun.

The life cycle of a star begins in a nebula. Describe how a main sequence star is formed from a nebula.

Describe how a main sequence star becomes a white dwarf.

Describe an experiment to determine the refractive index of a glass block. In your answer you should include • a labelled diagram • the apparatus needed • the method used

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

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

Give two uses of total internal reflection. 1 2

The diagram shows a fishing boat fitted with a high frequency sound wave emitter. The boat is above some fish. emitter fish The high frequency sound waves travel from the emitter to the fish and then back to the emitter, where they are detected.

Name the wave behaviour that causes the sound waves to change direction when they reach the fish.

The table gives some data about the sound waves used. frequency of sound waves 4.0 MHz speed of sound waves in water 1500 m/s time between emission and detection of sound waves 43 ms Calculate the distance between the sound wave emitter and the fish. distance = m

High frequency sound waves decrease in amplitude as they travel through soft tissue in the human body. The graph shows this decrease in amplitude for three different high frequency sound waves. 100 Relative amplitude (%) 50 2 MHz 10 MHz 4 MHz 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Distance travelled in cm

Estimate the distance travelled by a 2 MHz wave when its amplitude is 25% of its original value. distance = cm

Describe what the graph shows about the penetrating ability of high frequency sound waves as they travel through soft tissue.

The diagram shows a circuit containing a cell, two switches and two resistors, R1 and R2 . switch 1 R1 switch 2 R2

A light emitting diode (LED) is represented using the symbol Draw a LED on the circuit diagram that will indicate when there is a current in resistor R1 .

Both switches in the circuit are now closed.

Draw an ammeter on the circuit diagram that will measure the current in the cell.

The voltage across the cell is 4.5 V. Explain how the voltage across R2 compares with the voltage across the cell.

Switch 1 is now opened whilst switch 2 remains closed.

State the formula linking energy transferred, charge and voltage.

The voltage across the cell stays constant at 4.5 V. Calculate the charge transferred through the cell when the cell transfers 4.1 J of energy. charge transferred = C

A student investigates how the current in resistor R2 varies with the voltage across it. Describe how the circuit could be modified for the student to do this investigation.

A student does an experiment to determine the acceleration due to gravity, g. The diagram shows the apparatus used. steel ball light gate A clamp stand transparent tube light gate B This is the student’s method.

• connect both light gates to a data logger
• drop a steel ball from rest at the top of the transparent tube
• record the speed of the ball at each light gate
• record the time taken for the ball to fall from light gate A to light gate B

The box shows the data recorded by the data logger. speed at A = 1.45 m/s speed at B = 4.20 m/s time from A to B = 0.286 s

Show that the acceleration of the steel ball is approximately 9.6 m/s² . acceleration = m/s²

Explain why the student’s value for the acceleration of the steel ball is lower than the accepted value for the acceleration due to gravity, g.

Calculate the distance between the light gates. distance = m

The student changes the distance between the light gates by varying the position of light gate B. The student measures the time taken for the steel ball to fall from light gate A to light gate B when the light gates are different distances apart. The table shows the student’s results. Distance between Time taken light gates in s in m 0.10 0.058 0.20 0.103 0.30 0.141 0.40 0.175 0.50 0.205 0.60 0.233 0.70 0.260

Plot a graph of the student’s results on the grid.

Draw the curve of best fit. Distance between light gates in m Time taken in s

Explain how the graph shows that the steel ball is accelerating as it falls.

The photograph shows a mechanic pumping air into a car tyre. (Source: Rido/Shutterstock)

Before being pumped into the tyre, some air has a volume of 0.0043 m³ at a pressure of 100 kPa. The pressure of this air inside the tyre is 270 kPa. Calculate the volume of this air inside the tyre, assuming the temperature of the air does not change. Give your answer in standard form. volume = m³

The car is fitted with a tyre pressure monitoring system. A warning light will show in the car if the air pressure in the tyre falls below 250 kPa.

Using ideas about particles, explain why the air pressure inside the tyre is lower on a cold winter day than on a warm summer day.

The air pressure in the tyre is 270 kPa when the air temperature is 20 °C. On a cold winter day, the temperature is 2 °C. Determine whether the tyre pressure warning light will show in the car on the cold winter day. [assume tyre volume does not change]

The photograph shows a recyclable box designed for transporting cold food. layered cardboard lid layered cardboard walls The box has these design features

• thick walls made from several layers of cardboard with air trapped between the layers
• a thick lid made from layers of cardboard Cold food and ice packs are placed in the box.

Give a reason why there is a net transfer of energy from the outside of the box to the inside of the box during transportation in a hot country.

Explain how the box is designed to reduce energy transfer by conduction.

Explain how the box is designed to reduce energy transfer by convection.

A student suggests that painting the inner surfaces of the box a different colour would help to reduce the rate of energy transfer to the cold food. Explain which colour the inner surfaces of the box should be painted.