Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

IGCSE PHYSICS > Unit 4 > Flashcards

Unit 4 Flashcards

1
Q

What are the forces between magnetic poles and magnetic materials?

A

Like poles (e.g., N-N or S-S) repel, and unlike poles (e.g., N-S) attract. Magnetic materials are attracted to magnets.

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

What is the difference between magnetized and unmagnetized materials?

A

Magnetized materials produce their own magnetic field, while unmagnetized materials do not.

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

What is induced magnetism?

A

It occurs when a magnetic material is temporarily magnetized by being in a magnetic field.

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

What are the properties of temporary magnets?

A

Temporary magnets (e.g., soft iron) lose their magnetism when removed from the magnetic field.

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

What are the properties of permanent magnets?

A

Permanent magnets (e.g., steel) retain their magnetism after being magnetized.

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

What is the difference between magnetic and non-magnetic materials?

A

Magnetic materials (like iron, cobalt, nickel) can be magnetized, while non-magnetic materials (like wood, plastic) cannot.

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

What is a magnetic field?

A

A region in which a magnetic pole or material experiences a force.

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

How can the pattern and direction of magnetic field lines around a bar magnet be shown?

A

By sprinkling iron filings or using a compass to show the field lines from N to S pole.

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

How is the direction of a magnetic field at a point determined?

A

It is the direction of the force on the N pole of a magnet at that point.

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

How can you plot magnetic field lines?

A

Using a compass or iron filings, place them around the magnet and observe the lines.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some uses of permanent magnets and electromagnets?

A

Permanent magnets are used in fridge doors, compasses, and loudspeakers. Electromagnets are used in cranes, electric bells, and relays.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What causes magnetic forces?

A

They arise from interactions between magnetic fields.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the spacing of magnetic field lines indicate?

A

Closer spacing indicates a stronger magnetic field.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the two types of charges, and how do they interact?

A

Positive and negative charges; like charges repel, unlike charges attract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can you detect electrostatic charges?

A

By rubbing materials to generate static electricity and observing attraction or repulsion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does friction charge solids?

A

By transferring electrons (negative charges) between materials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is an experiment to distinguish between conductors and insulators?

A

Use a circuit with a bulb; conductors allow current to flow (bulb lights), insulators do not.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Give examples of electrical conductors and insulators.

A

Conductors: copper, aluminum. Insulators: plastic, rubber.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In what unit is charge measured?

A

Charge is measured in coulombs (C).

20
Q

What is an electric field?

A

A region where a charge experiences a force.

21
Q

What is the direction of an electric field at a point?

A

It is the direction of the force on a positive charge at that point.

22
Q

Describe electric field patterns around a point charge.

A

Radial lines outward for positive, inward for negative.

23
Q

Describe electric field patterns around a charged sphere.

A

Similar to a point charge.

24
Q

Describe electric field patterns around parallel plates.

A

Uniform lines between plates, perpendicular to the surface.

25
Q

What is the relationship between electric current and charge flow?

A

Electric current is the rate of flow of charge.

26
Q

How is current measured?

A

Using ammeters (analogue or digital).

27
Q

What is electrical conduction in metals?

A

It occurs when free electrons move through the metal, carrying charge.

28
Q

What is the difference between direct and alternating current?

A

Direct current (d.c.) flows in one direction; alternating current (a.c.) reverses direction periodically.

29
Q

Write the equation for current.

A

I = Q / t, where I is current, Q is charge, and t is time.

30
Q

What is conventional current?

A

It flows from positive to negative, opposite to electron flow.

31
Q

Define e.m.f.

A

The work done per unit charge by a source to move the charge around a complete circuit.

32
Q

Define potential difference.

A

The work done per unit charge as it passes through a component.

33
Q

How is e.m.f. or p.d. calculated?

A

E = W / Q, where W is work, and Q is charge.

34
Q

Write the formula for resistance.

A

R = V / I, where R is resistance, V is voltage, and I is current.

35
Q

What factors affect resistance in a wire?

A

Resistance is directly proportional to length and inversely proportional to cross-sectional area.

36
Q

Write the formula for electrical power.

A

P = IV, where P is power, I is current, and V is voltage.

37
Q

Write the formula for electrical energy.

A

E = IVt, where E is energy, I is current, V is voltage, and t is time.

38
Q

What is a kilowatt-hour (kWh)?

A

The energy used by a 1 kW device in 1 hour.

39
Q

What are the hazards of damaged insulation?

A

It can lead to electric shocks or short circuits.

40
Q

What are the hazards of overheating cables?

A

It may cause electrical fires.

41
Q

Why is dampness dangerous in electrical circuits?

A

Water conducts electricity, leading to electric shocks.

42
Q

What are the hazards of overloading plugs or extension leads?

A

Excess current can cause overheating and fires.

43
Q

What wires make up a mains circuit?

A

Live wire, neutral wire, and earth wire.

44
Q

Why must a switch be connected to the live wire?

A

To safely disconnect the appliance from the high-voltage supply.

45
Q

What is the purpose of trip switches and fuses?

A

To break the circuit when the current exceeds safe levels, preventing damage or injury.

46
Q

Why must the outer casing of an appliance be non-conducting or earthed?

A

To prevent electric shock if the casing becomes live.

47
Q

What is the purpose of a fuse in a double-insulated appliance?

A

To protect the appliance and cabling from excessive current.

IGCSE PHYSICS (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions