Practice Paper 2 (Edexcel IGCSE Science)

The diagram shows four planets, P, Q, R and S, orbiting a star.

Planet Q has a moon.

On the diagram, draw the orbit of this moon.

On the diagram from part (a), draw the orbit of a comet.

Planets nearer to the star take less time to orbit the star.

Suggest why.

As the planets orbit the star, the distances between the planets change.

Planet P is 200 million km from the star and planet R is 50 million km from the star.

(i) Calculate the maximum distance between planet P and planet R.

maximum distance = ........................................... million km [1]

(ii) Calculate the minimum distance between planet P and planet R.

maximum distance = ........................................... million km [1]

Describe how stars are formed.

Add words from the box in the gaps to make the sentences correct.

(i) Nuclear ...................................... releases energy inside stars.

(ii) A star is stable during the 'main sequence' period in its life because the ...................................... within it are ...................................... .

The life cycle of a star after the 'main sequence' period depends on the size of the star. A particular star is much larger in size than the Sun.

Complete the stages of the life cycle of this star.

A student investigates how the resistance of a thermistor varies with temperature.

Draw the circuit symbol for a thermistor.

A light-dependent resistor (LDR) can be used as a sensor to detect light intensity.

Sketch a graph on the axes below to show how the resistance of an LDR varies as the light intensity changes.

Which quantity is defined as the rate of flow of charge?

Which quantity is defined as the energy transferred per unit charge passed?

Batteries supply direct current (d.c).

Another type of current is alternating current (a.c).

Draw the voltage-time graph for a d.c. supply on the graph below.

Draw the voltage-time graph for an a.c. supply on the graph below.

Each statement in the table below may be true about d.c, true about a.c, or true for both d.c and a.c.

Place a tick in the correct box in each row.

Which of these is a unit for energy?

A flying squirrel is an animal that can glide through the air. It spreads out its limbs to stretch out a membrane that helps it to glide.

^{© Robert Savannah}

The flying squirrel glides from P to Q with a constant velocity.

The velocity of the squirrel decreases to zero when it reaches the second tree because

A bus travels along a straight road.

The graph shows how the velocity of the bus changes during a short journey.

(i) State the velocity of the bus after 25 s.

velocity = .............................m/s

(ii) How long is the bus stationary during its journey?

time = .............................s

(i) State the equation linking acceleration, change in velocity and time taken.

(ii) Calculate the acceleration of the bus during the first 10 seconds.

Give the unit.

acceleration = .......................... unit ..........................

(i) State the equation linking average speed, distance moved and time taken.

(ii) The bus moves a total distance of 390 m during the journey.

Calculate the average speed of the bus.

average speed = ......................... m/s

The bus travels further in the first 30 seconds of its journey than it does during the last 30 seconds.

Explain how the graph shows this.

The diagram shows a magnet held above a coil. The coil is connected to a voltmeter.

The magnet is released and falls into the coil.

(i) Explain why the voltmeter shows a reading.

(ii) The magnet is released from a greater height. How does this affect the voltmeter? Explain your answer.

State how the voltmeter reading changes when the same magnet

(i) moves more slowly into the coil.

(ii) moves into a coil with more turns.

(iii) is reversed so the S-pole enters the coil first.

The photograph shows a small electric motor.

Explain why the coil starts to spin when the switch is closed.

(i) Suggest how to make the coil spin in the opposite direction.

(ii) Suggest how to make the coil spin more slowly.

In a different motor, the magnets are curved and there is a piece of iron inside the coil. The iron increases the strength of the magnetic field through the coil.

Suggest how the curved magnets and the piece of iron improve the performance of the electric motor.

The diagram shows the main parts of a nuclear reactor.

Draw a line linking each part of the reactor with its main function.

The first one has been done for you.

In a fission reaction, energy is transferred from the nuclear store of the particles to which store?

Explain the role of the moderator in a fission reaction.

Explain, in terms of neutrons, what is meant by controlled nuclear fission.

Tellurium-120 is an isotope of tellurium.

It has the symbol ${}_{52}^{120}{Te}$

The number of protons, neutrons and electrons in a neutral tellurium-120 atom is

lodine-131 is used to treat thyroid cancer. This radioactive isotope is allowed to enter the tumour.

Explain why iodine-131 is suitable for this treatment.

The object shown in the photograph is an old, brass mass.

It is marked 500 g.

A student puts the mass on an electronic balance.

The electronic balance reading is 498.2 g.

The student concludes:

Evaluate this conclusion.

The student wants to find the density of the old, brass mass.

First, he obtains a correct value for the mass. What else must he do to find the density?

A fission reactor is cooled with helium gas. The gas enters the reactor at 500°C.

What is this temperature in kelvin?

Helium gas enters the reactor at a pressure of 8.40 MPa and leaves the reactor at a temperature of 1170 K.

Calculate the pressure of the helium gas as it leaves the reactor.

[Assume the volume of the gas does not change.]

Explain how the student can use a glass block to find an accurate value for the refractive index of glass.