Test Revison

Question 1

What is an electrical conductor?

Answer 1

A material which easily allows an electric current.

Question 2

What is an electrical insulator?

Answer 2

A material which does not allow an electric current.

Question 3

Name some good electrical conductors.

Answer 3

Any metal (some are better than others!), graphite (a form of carbon), salt water.

Question 4

Name some good electrical insulators.

Answer 4

Wood, plastic (most non-metals in fact).

Question 5

What is the circuit symbol for a cell?

Answer 5

Draw the circuit symbol for a cell.

Question 6

What is the circuit symbol for a battery?

Answer 6

Draw the circuit symbol for a battery.

Question 7

What is the circuit symbol for a bulb?

Answer 7

Draw the circuit symbol for a bulb.

Question 8

What is the circuit symbol for a switch?

Answer 8

Draw the circuit symbol for a switch.

Question 9

What is the circuit symbol for a variable resistor?

Answer 9

Draw the circuit symbol for a variable resistor.

Question 10

What is the circuit symbol for an ammeter?

Answer 10

Draw the circuit symbol for an ammeter.

Question 11

What instrument is used to measure current?

Answer 11

Ammeter.

Question 12

What does an ammeter measure?

Answer 12

Current.

Question 13

What is the unit of current and what is its symbol?

Answer 13

Amperes, A.

Question 14

If I increase the number of cells in my battery, what will happen to the current?

Answer 14

The current will increase.

Question 15

When the charge moves through the cell, what does it gain?

Answer 15

Energy.

Question 16

Energy per unit charge is also known as?

Answer 16

Potential.

Question 17

What is the unit of potential?

Answer 17

Volt, V.

Question 18

What happens if I connect more bulbs in series?

Answer 18

The resistance will increase and the current will decrease.

Question 19

What is the unit of resistance?

Answer 19

Ohm, Ω.

Question 20

What is current?

Answer 20

The amount of charge passing a point each second.

Question 21

What is the important rule to remember at a junction in a circuit?

Answer 21

Total current in = total current out.

Question 22

Which poles of a magnet attract each other?

Answer 22

The opposite poles (North and South).

Question 23

What happens when like poles of magnets come together?

Answer 23

They repel.

Question 24

Give some examples of magnetic materials.

Answer 24

Iron, Steel, Cobalt, Nickel.

Question 25

Give some examples of non-magnetic materials.

Answer 25

Plastic, Wood, Paper, Rubber, Glass.

Question 26

Why does the Earth have a magnetic field?

Answer 26

The core of the earth is a rotating ball of Iron.

Question 27

What is a magnetic field?

Answer 27

The region around a magnet where other magnetic materials experience a force.

Question 28

How are magnetic fields represented in diagrams?

Answer 28

Magnetic field lines.

Question 29

How could you visualize the field around a magnet?

Answer 29

Iron filings, or using a compass.

Question 30

What is the shape of a magnetic field around a wire?

Answer 30

Circular.

Question 31

How can we tell the direction of the magnetic field lines around a wire?

Answer 31

Right hand 'thumbs up' rule. Thumb points in the direction of the current, the fingers curl in the direction of the field.

Question 32

What do we call the effect when a current flows in a wire and generates a magnetic field?

Answer 32

Electromagnetism.

Question 33

What is the magnetic field around a coil/solenoid?

Answer 33

Draw the magnetic field around a coil/solenoid.

Question 34

Name 3 ways to increase the strength of the magnetic field around a solenoid.

Answer 34

* Increase the current * Increase the number of turns on the coil * Add an iron core.

Question 35

What is one major advantage of an electromagnet compared to a permanent magnet?

Answer 35

Electromagnets can be switched on and off.

Question 36

What is a relay circuit used for?

Answer 36

To activate high voltage circuits using low voltage circuits (this protects the user from high currents).

Question 37

List some uses of electromagnets.

Answer 37

In relays (e.g. to switch off floodlights or x-ray machines in hospitals), in scrapyards to move parts, maglev trains, in electric motors, in rollercoaster braking.