Physics Flashcards

Collect lost marks on IGCSE Physics

1
Q

A man drops a brass key into the oil and it sinks to the bottom of the oil.
Explain how attaching the key to a piece of wood could prevent the key from sinking.

A

The density of the wood and the key combined is less than the density of oil.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Explain, in terms of molecules, why it is possible to compress a gas, but not a liquid.

A

Gas molecules are very far apart
Molecules of liquid are very close together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Evaporation occurs.
Explain, in terms of molecules, why the temperature has decreased.

A

Most energetic particles escape.
Less energetic particles remain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A quantity of gas is contained in a sealed container of fixed volume. The temperature of the gas is increased. State, in terms of molecules, two reasons why the pressure of the gas increases.

A

Particles hit walls with more force.
Particles have more momentum.
Particles hit walls more frequently.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The sound wave passes from the sea-water into the air
State what happens, if anything, to
1. The frequency of the sound
2. The speed of the sound

A

Unchanged
Slower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe one use of optical fibres in medicine. You may draw a diagram.

A

Endoscope
Using a bundle of optical fibres
Doctors look inside the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A d.c. supply is connected to the input of a transformer.
When switch S is first closed, the needle of the galvanometer deflects, then returns to zero. Explain why the brief deflection occurs.

A

There is a change in current.
This produces a changing magnetic field that travels to the secondary coil and causes a voltage to be induced.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A same amount of cold water as in an insulating bowl is poured into a metal
bowl.
The metal bowl is the same shape and size as the insulating bowl.
The decrease in temperature is less than before.
Explain why.

A

Metal is a good conductor of heat.
Metal conducts heat away from the water and into the surroundings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Suggest why there is a current in the wire between the sphere and earth.

A

Electrons are transferred from the sphere to the earth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly