Electricity

Question 1

symbol for bulb/lamp

Answer 1

a circle with a cross in it

Question 2

symbol for battery

Answer 2

two vertical lines, the longer line represents a + and the shorter line represents a -

Question 3

symbol for wire

Answer 3

line

Question 4

symbol for a switch

Answer 4

two dots a line across it if the switch is on, the line lifted up represents that the switch is off

Question 5

conductors

Answer 5

allow for the flow of electricity

Question 6

insulators

Answer 6

minimise/don’t allow the flow of electricity

Question 7

Does acrylic conduct electricity?

Answer 7

No

Question 8

Does nickel conduct electricity?

Answer 8

Yes

Question 9

Does lead conduct electricity?

Answer 9

Yes

Question 10

Does bone conduct electricity?

Answer 10

No

Question 11

Does carbon conduct electricity?

Answer 11

Yes

Question 12

Does polystyrene electricity?

Answer 12

No

Question 13

Does soft wood conduct electricity?

Answer 13

No

Question 14

Does zinc conduct electricity?

Answer 14

Yes

Question 15

Does steel conduct electricity?

Answer 15

Yes

Question 16

The current in series circuit

Answer 16

The current in a series circuit has the same value at every point. The current does not et lost or used by the circuit.

Question 17

Why does an open switch stop a current flowing?

Answer 17

This is because the circuit isn’t complete.

Question 18

resistant increases as components added

Answer 18

current decreases as resistance increases

Question 19

short circuit

Answer 19

A short circuit is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical independence. This result is in an excessive current flowing through the circuit. The opposite of a short circuit is an “open circuit”, which is an infinite resistance between two nodes.

Question 20

If we use more batteries the current will be _____ so the bulbs will be _____. If we use more bulbs the current will be _____ so the bulbs will be _____. The extra bulbs cause more ______ in the circuit due to their thin wire _____. So there are ____ ways of changing the current in a circuit.

Answer 20

If we use more batteries the current will be greater so the bulbs will be brighter. If we use more bulbs the current will be lower so the bulbs will be dimmer. The extra bulbs cause more resistance in the circuit due to their thin wire filament. So there are many ways of changing the current in a circuit.

Question 21

Are the bulbs in a parallel circuit brighter than bulbs in a series circuit?

Answer 21

Yes

Question 22

Parallel circuit formula:

Answer 22

A1=A2+A3

Question 23

current:

Answer 23

a measure of how many charges flow past at a certain time (rate of flow)

Question 24

Bakery and supermarket analogy:

Answer 24

• empty vans collect bread at the bakery
• these vans are full of bread
• the vans deliver bread to the supermarket
• these vans are empty and go back to the bakery to collect more energy
• charges collect energy at the battery
• charges are atom sized particles already in the wire. The charges carry energy
• charges deliver energy to the bulb where it is transferred to heat and light
• charges return to the battery to collect more energy

Question 25

charges:

Answer 25

atom sized particles in the wire

Question 26

If there is one possible flow for a circuit then...

Answer 26

the charge will be the same anywhere on the circuit.

Question 27

Colour of live wire

Answer 27

Brown

Question 28

Colour of Earth wire

Answer 28

Green and yellow

Question 29

Colour of neutral wire

Answer 29

Blue

Question 30

Nerves

Answer 30

Electrical signal travel around our bodies along the nerves. Nerves are good conductors of electricity. The muscles contract not allowing you to let go of the electrical object.

Question 31

What does the Earth wire do?

Answer 31

If the casing becomes live the Earth wire will redirect the electrical current down back to the plug which is a much faster route for it than going through a human and into the ground.

Question 32

Fuse

Answer 32

A thin piece of wire which is thinner than the rest of the wire in the circuit. If the electric current gets too hot the fuse will melt and blow and this breaks the circuit do that the circuit is incomplete.

Question 33

Where is the fuse put?

Answer 33

The live wire as it has the least resistance so there is a lot of current and it would be able to break the circuit if it becomes incomplete.

Question 34

Hazards of mains supply:

Answer 34

- electric shock burns from contact with live parts - injury from exposure to arcing, fire from faulty electrical equipment or installations - explosion caused by unsuitable electrical apparatus or static electricity igniting flammable vapours or dusts