Cambridge IGCSE Physics - 0625 - Core Paper 1 2015 Winter Zone 3

A student uses a measuring cylinder to measure the volume of a quantity of water. Which action would make her result less accurate?

The diagram shows the distance-time graph for a car.
At which labelled point is the car moving with constant speed?

A car travels along the route PQRST in 30 minutes.

What is the average speed of the car?

What is the weight of an object?

The mass of a piece of metal is 1200 g.
A measuring cylinder contains 150 cm³ of water.
The piece of metal is put into the measuring cylinder. The water level rises to 250 cm³ and covers the metal.
What is the density of the metal?

A heavy beam rests on two supports. The diagram shows the only three forces $F_1$, $F_2$ and $F_3$ acting on the beam. The beam is in equilibrium. Which statement is correct?

A heavy truck on wheels has a platform attached to it.
A man stands on the platform.
The truck does not fall over.
Which position A, B, C or D could be the centre of mass of the whole system (truck, platform and man)?

Which row gives the energy change in a battery and the energy change in a solar cell?
[Table_1]

Electrical energy may be obtained from nuclear fission. In which order is the energy transferred in this process?

A man is in contact with the floor. In which of these situations does he produce the least pressure on the floor?

The water in a lake is at 5°C. A diver measures the pressure of the water at two different depths in the lake. He repeats the measurements on a different day when the water is at 15°C.
The density of the water decreases when its temperature increases.
Which combination of depth and temperature produces the greatest water pressure?
[Table_1]

A car tyre has a constant volume. Why does the pressure of the air in the tyre increase when its temperature increases?

A swimmer feels cold after leaving warm water on a warm, windy day. Why does she feel cold even though the air is warm?

A circular metal disc is heated. Which quantity decreases?

The diagram shows a mercury-in-glass thermometer. The scale of the thermometer has not been marked.

The length $l$ increases uniformly with temperature.
The length $l$ is measured when the thermometer bulb is placed in water at $0\, ^\circ C$, and also when it is in water at $100\, ^\circ C$. The table shows the results.
[Table_1: temperature/$^\circ C$ length $l/$cm]
| temperature/$^\circ C$ | length $l/$cm |
| ----------------------- | ------------ |
| 0 | 2.0 |
| 100 | 26.0 |

What is the value of $l$ when the bulb is placed in water at $50\, ^\circ C$?

A heating engineer fits a heater to the ceiling of an office so that workers in the office are kept warm.
How does thermal energy reach the workers below the heater?

Which row shows how heating changes the density of air, and the name of the method of energy transfer caused by this density change?
[Table_1]

Which row correctly defines a type of wave and gives a correct example? [Table_1]

A water wave moves quickly in deep water.

The wave now enters shallow water and its speed decreases.
Which row shows what happens to the frequency of the wave, and what happens to the wavelength of the wave?

The diagram shows the electromagnetic spectrum.

A word is missing from the label below the spectrum.
Which word is missing?

A student draws a diagram representing three rays of light from point P passing through a converging lens. Each point labelled F is a principal focus of the lens.

Which of the rays has the student drawn correctly?

The diagram shows a ray of light travelling in a substance P. The ray reaches a boundary with a substance Q. Total internal reflection occurs at the boundary.
Which row contains correct statements about angle X and about the optical density of substance Q?
[Table_1]

A pulse of sound is produced at the bottom of a boat. The sound travels through the water and is reflected from the sea bed. 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 sea bed?

Sounds are produced by vibrating objects. A certain object vibrates but a person nearby cannot hear any sound.
Which statement could explain why nothing is heard?

Which metal could be used for a permanent magnet and which metal could be used for the core of an electromagnet? [Table_1]

Which procedure may be used to demagnetise a steel bar?

A plastic rod is rubbed with a cotton cloth. This process causes the rod and the cloth to become charged. These charges cause a force between the rod and the cloth.
Which row compares the charges on the rod and the cloth, and describes the effect of the force between the rod and the cloth?
[Table_1]

A metal wire of circular cross-section has diameter $d$ and length $l$.
Which pair of changes, if both are carried out, must increase the resistance of the wire?

The circuit shown contains a battery, a $6.0\,\Omega$ resistor and two meters X and Y. One meter records current and one meter records potential difference.

Which row shows possible values for the readings on the meters?

A student designs a circuit to switch on a lamp after a time delay.
Which components are used in a time-delay circuit?

Identical resistors are connected together to form arrangements X, Y and Z.

What is the correct order of the resistances of the arrangements from the largest to the smallest?

The diagram shows a potential divider circuit.
The resistance of the variable resistor is increased.
Which row shows what happens to the readings on voltmeter P and on voltmeter Q?

Four lamps are each labelled '60 W 230 V'.
In which circuit are the lamps connected so that they operate at normal brightness?

A student investigates electromagnetic induction. She has a bar magnet and a coil of wire that is connected to a sensitive ammeter.

Which movement does not cause a reading on the ammeter?

The primary coil of a transformer has 200 turns. This primary coil is connected to an a.c. power supply of 25V.
A voltmeter connected across the secondary coil reads 50V.
[Image]
How many turns are on the secondary coil?

A current-carrying coil in a magnetic field experiences a turning effect.
How can the turning effect be increased?

The diagram shows a cathode-ray tube. The tube is not working.

Which change should be made to make the tube work to produce cathode rays?

A radioactive nucleus contains 128 nucleons. It emits a $\beta$-particle.
How many nucleons are now in the nucleus?

A student investigates how the radiation from a radioactive source changes with time. The table shows the results from the detector used by the student.

[Table_1]

The experiment is repeated by many other students, who also measure the count rate every two minutes.
The half-life of the source is known to be exactly 2.0 minutes.

Why is the measured count rate always greater than half the previous value?

The nuclide notation for radium-226 is $^{226}_{88}\text{Ra}$.
How many electrons orbit the nucleus of a neutral atom of radium-226?