Cambridge IGCSE Physics - 0625 - Core Paper 1 2020 Summer Zone 2

Five athletes P, Q, R, S and T compete in a race. The table shows the finishing times for the athletes.

[Table_1]

Which statement is correct?

The graph shows how the speed of an object varies with time. At which labelled time is the acceleration greatest?

Which statement about acceleration is correct?

Two metal blocks P and Q have identical dimensions. They hang on identical spring balances.
Which statement about P and Q is correct?

A space probe is taken from the Earth to Mars.
The force of gravity on the surface of Mars is less than the force of gravity on the surface of the Earth.
How do the weight and the mass of a space probe on the surface of Mars compare to their values when the probe is on the surface of the Earth?
[Table_1]

Water has a density of 1000 kg/m^3.
A rectangular swimming pool has an average depth of 1.6 m.
The length of the pool is 25 m.
The width of the pool is 10 m.
What is the mass of the water in the swimming pool?

The diagram shows an extension–load graph for a spring.

An empty can of weight 3.0 N is suspended from the spring.
Liquid is poured into the can until the extension is 8.0 cm.
What is the weight of the liquid?

What is meant by the moment of a force on an object?

Which energy resource is not renewable?

Two motors X and Y lift loads of the same weight through the same vertical distance.
Motor X is more efficient than motor Y.
Which statement about the motors is correct?

A man can either take an escalator or a lift to travel up between two floors in a hotel.

The escalator takes 20 seconds to carry the man between the two floors. The useful work done against gravity is $W$. The useful power developed is $P$.
The lift takes 30 seconds to carry the same man between the same two floors.
How much useful work against gravity is done by the lift, and how much useful power is developed by the lift?

The diagram shows a solid block resting on a bench. The dimensions of the block are shown. On which labelled surface should the block rest to produce the smallest pressure on the bench?

A beaker contains a liquid.

On what does the liquid pressure at position X depend?

Evaporation occurs from the surface of a pool of water.
Which statement describes this change of state?

A gas, in a sealed container, is compressed slowly so that its temperature does not change.
What happens to the molecules of the gas as a result of this compression?

The diagram shows a liquid-in-glass thermometer.
What is the temperature difference between the two fixed points on the Celsius scale?

A metal block is left overnight in a cool, shady room. In the morning, the metal block is moved into warm surroundings. Which statement about the metal block is correct in the morning?

The diagrams show four blocks of steel. The blocks are all drawn to the same scale. The same quantity of thermal energy is given to each block. Which block shows the greatest rise in temperature?

A room is heated by a radiator. The diagrams X and Y show two possible circulations of hot air, which heat the room.

Which diagram and reason explain the heating of the room by convection?

Two similar liquid-in-glass thermometers P and Q are placed in direct sunlight. The bulb of thermometer P is painted white. The bulb of thermometer Q is painted black.
How and why would the thermometer readings differ?

The diagram shows a wave.

What are the amplitude and the wavelength of this wave?

Waves travel more quickly on the surface of water when the water is deep. A stone is dropped at point X into a pool of varying depth. The diagram shows the first three wavefronts on the surface of the pool. The region between X and which labelled point is likely to be the deepest?

The diagram shows a ray of light incident on the surface of a glass block.

The ray of light is partially reflected back into the air and partially refracted into the glass block.
Which row correctly identifies the angle of reflection and the angle of refraction?

A beam of light consists of yellow and blue light.
The beam of light is incident on a glass prism.
Which diagram is correct?

An intruder alarm sensor detects that a person is warmer than his surroundings.
Which type of electromagnetic wave does the sensor detect?

A dolphin sends out a sound wave. An echo returns 0.010s later from a fish which is 7.5m from the dolphin.

What is the speed of the sound wave in water?

The diagrams show two bar magnets which are attracting each other.
Which diagram shows the magnetic field pattern between the poles?

Four nails A, B, C and D are tested to find which makes the strongest permanent magnet.
One of the nails is placed against a bar magnet and the number of paper clips which the nail can support is recorded.



The bar magnet is then removed and the number of paper clips remaining attached to the nail is recorded. Each nail is tested individually.
Which nail becomes the strongest permanent magnet?

[Table_1] number of paper clips attached to the nail
| | | |
|---|---|---|
| bar magnet present | bar magnet removed |
| A | 2 | 0 |
| B | 2 | 1 |
| C | 4 | 3 |
| D | 5 | 2 |

A cloth is used to rub an uncharged plastic rod.
Both the rod and the cloth become charged.
Why does the plastic rod become negatively charged and the cloth become positively charged?

The diagram shows a circuit. The wire between P and Q can be removed and replaced by a circuit component. Where should a voltmeter be connected to measure the potential difference (p.d.) across the lamp?

A student uses the circuit shown to determine the resistance of two identical resistors.
The voltmeter reading is 2.2 V and the ammeter reading is 0.25 A.
What is the resistance of each resistor?

The circuit shown contains five lamps J, K, L, M and N. All the lamps are glowing.

One lamp is removed and two other lamps go out.
Which lamp is removed?

The diagram shows a control circuit. The lamp is lit.


The temperature of the surroundings increases. What will happen to the brightness of the lamp?

A student constructs four circuits, each containing a fuse.
The fuse blows in one circuit and both lamps in the circuit go out.
In which circuit does the fuse blow and both lamps go out?

The diagrams P, Q and R show three voltage–time graphs.
Which graphs show an alternating voltage?

The diagram shows a transformer.

Which statement about this transformer is correct?

A nuclide of the element iron has the symbol shown.

$^{56}_{26}\text{Fe}$

What does a neutral atom of this nuclide contain?
[Table_1]

Which statement about the nuclei of all atoms is correct?

A thin sheet of paper is placed between a radioactive source and a radiation detector. The count rate falls to a very low reading.

From this result, which type of radiation is the source emitting?

A radioactive isotope has a half-life of 120 minutes.
It emits radiation at a rate of 100 particles per second.
How long does it take for the rate of emission to fall to 25 particles per second?