Cambridge IGCSE Physics - 0625 - Core Paper 1 2019 Summer Zone 1

A digital stop-clock measures time in minutes and seconds.
The stop-clock reads 00:50 when it is started (i.e. 00 minutes 50 seconds).
It reads 02:10 when it is stopped.
What is the shortest possible time that has elapsed between starting and stopping the stop-clock?

A long-distance runner wishes to calculate her average speed for a race.
Which calculation should she use?

A heavy metal ball falls vertically downwards through air past four equally spaced levels J, K, L and M.

The times taken to fall from one level to the next are measured.
Where is the speed of the ball greatest and which time is shortest?

An arrow travels horizontally in a straight line at constant speed. In which direction does the weight act?

Two rectangular blocks consist of different materials.
Four different methods are suggested to compare the two masses.
1 Compare the accelerations with which they fall freely.
2 Compare the values of their lengths × breadths × heights.
3 Hang each in turn from the same spring. Compare the extensions.
4 Place one in the right-hand pan of a beam balance and the other in the left-hand pan.
Which methods give a comparison of the two masses?

The diagrams show four solid blocks with their dimensions and masses.
Which block has the greatest density?

A mass of 20 kg is held stationary by a rope passing over a frictionless pulley.
What is the tension $T$ in the rope?

A spring is suspended from a stand. Loads are added and the extensions are measured.

Which graph shows the result of plotting extension against load?

A wooden bar is pivoted at its centre so that it can rotate freely. Two equal forces $F$ are applied to the bar.
In which diagram is the turning effect greatest?

A machine is very efficient. What does this mean?

An object is lifted vertically by a motor.
In which example is the power produced the greatest?

Four identical submarines P, Q, R and S are lowered from one depth to another in water of a constant density.
The initial and final depths of each submarine are shown in the diagram.

Which row is correct for the difference in pressure from the initial to final depth of each submarine?

The diagram shows a stone suspended on a string under the surface of a liquid. The stone experiences a pressure caused by the liquid.
What would increase the pressure on the stone?

Why can a gas be compressed easily into a smaller volume?

When a liquid evaporates, some molecules escape. The temperature of the remaining liquid changes. What is the effect on the temperature and from where do the molecules escape? [Table_1]

What happens when a metal block is heated?

A night storage heater contains a large block of material that is heated electrically during the night. During the day the block cools down, releasing thermal energy into the room.
Which thermal capacity and which night-time temperature increase will cause the most energy to be stored by the block?

| thermal capacity of block | night-time temperature increase |
| --- | --- |
| A | large | large |
| B | large | small |
| C | small | large |
| D | small | small |

The diagram shows the changes of state P, Q, R and S that occur in solids, liquids and gases when they gain or lose thermal energy.



What is the name of change R?

In which does thermal conduction not occur?

The metal surface of a kettle is hot.
What happens to the cool air outside the kettle when it comes into contact with the hot kettle?

Ultrasound is used in a hospital to scan a patient. Ultrasound refracts at the boundary between muscle and bone because it travels at a greater speed in bone.
Which change takes place when the ultrasound travels from muscle into bone?

The diagram shows a cork with a weight attached so that the cork floats upright in water.
Transverse waves travel across the water from X to Y.
In which direction do the waves make the cork move?

An object is placed 30 cm in front of a plane mirror. Which statement describes the image of the object?

The diagram shows light incident at a glass-air boundary. The angle of incidence $i$ of the ray is greater than the critical angle.
Which line shows the path of the light after it meets the boundary?

The diagram shows radiation from a lamp passing through a prism.

Which type of radiation is found at P?

A pulse of sound is produced at the bottom of a boat. The sound travels through the water and is reflected from a shoal of fish. The sound reaches the boat again after 1.2 s. The speed of sound in the water is 1500 m/s.
How far below the bottom of the boat is the shoal of fish?

Which range is approximately correct for the audio frequencies that can be detected by a healthy human ear?

Why is soft iron used for the core of an electromagnet?

An iron ball on a horizontal wooden table rolls near the north pole of a bar magnet which is lying on the table.
Which diagram shows the most likely path of the ball, as seen from above the table?

Diagram 1 shows two thin, uncharged strips of plastic.
Diagram 2 shows the same strips after they have been rubbed with a dry cloth.

Which row describes the charge on the strips after rubbing, and the force between the strips after rubbing?

A voltmeter and an ammeter are used to measure the resistance of a resistor.
Which diagram shows the voltmeter and the ammeter correctly connected?

A student sets up four circuits. In which circuit is there a heater in series with a fuse?

The diagram shows a circuit containing a d.c. power supply, a motor and a variable resistor. Three ammeters X, Y and Z show the current in different parts of the circuit. The reading on X is 4.0A. Which statement is correct?

A lamp is to be connected in a circuit so that the potential difference (p.d.) across it can be varied from 0 to 6V.
Which circuit would be most suitable?

An electric heater is plugged into the mains supply using a fused plug.
The current in the heater is 10 A.
The cable attached to the heater is rated at 15 A.
The fuses available are rated at 1 A, 3 A, 5 A and 13 A.
Which fuse should be used?

A bar magnet is held near a coil of wire. The coil is connected to a sensitive voltmeter.
The N-pole of the magnet is moved quickly towards the coil. The voltmeter shows a reading of +10mV.
The N-pole of the magnet is then moved slowly away from the same end of the coil. The reading on the voltmeter is observed.
Which voltmeter reading is possible?

Four small compasses are placed around a solenoid.



A current is now switched on in the solenoid.

Which diagram shows possible new directions of the compass needles?

Four nuclides are represented below.

$^6_3 \text{E} \phantom{space} ^7_3 \text{G} \phantom{space} ^6_4 \text{L} \phantom{space} ^7_5 \text{M}$

Which pair of nuclides are isotopes of the same element?

A student measures the level of radiation emitted from a radioactive substance. He places a detector very close to the substance. He puts different absorbers between the radioactive substance and the detector.
[Image_1: Diagram showing radioactive substance, detector, absorber, and counter]
The student’s results are shown. These results are corrected for background radiation.
[Table_1: Absorber | Counter Reading (counts per minute); none | 95; thin paper | 52; few mm of aluminium | 52; several cm of lead | 12]
Which types of radiation are being emitted by the substance?

The nuclei of the atoms in a substance are changing randomly and emitting radiation. What is happening to the substance?