Electricity

Question 1

What is an electric current?

Answer 1

The flow of electrical charge

Question 2

What is current measured in?

Answer 2

Amps

Question 3

What is electric charge measured in?

Answer 3

Coulombs

Question 4

What is the resistance?

Answer 4

A measure of how it resists the flow of charge

Question 5

What happens when the resistance is high?

Answer 5

Difficult for charge to flow
Lower the current

Question 6

What is resistance measured in?

Answer 6

Ohms

Question 7

What does potential difference tell us?

Answer 7

The difference in electrical potential from one point in a circuit to another

Question 8

What can potential difference be thought of as?

Answer 8

Electrical push

Question 9

What happens if the potential difference is bigger across a component?

Answer 9

The flow of charge is greater through the component
The bigger the current

Question 10

What is potential difference measured in?

Answer 10

Volts

Question 11

What do potential difference-current graphs show?

Answer 11

The relationship between potential difference and current for any component

Question 12

What is an ohmic conductor?

Answer 12

A resistor in which the current is directly proportional to the potential difference at a constant temperature

Question 13

How will current through a diode?

Answer 13

In one direction

Question 14

What happens as the resistance of a thermistor decreases?

Answer 14

The temperature increases

Question 15

What happens as light intensity increases in LDRs?

Answer 15

The resistance decreases

Question 16

What happens as the current through a filament lamp increases?

Answer 16

The temperature increases

Question 17

What are the two types of circuit?

Answer 17

Series
Parallel

Question 18

What does the power of a device depend on?

Answer 18

The potential difference across it and the current flowing through it

Question 19

What is a direct current?

Answer 19

Has a potential difference that is always positives or always negative
Used in batteries

Question 20

What is an alternating current?

Answer 20

Has a potential difference that alternates from positive to negative
Used in mains electricity

Question 21

What V and Hz used in the UK mains?

Answer 21

230V, 50Hz

Question 22

What colour is the live wire?

Answer 22

Brown

Question 23

What colour is the neutral wire?

Answer 23

Blue

Question 24

What colour is the earth wire?

Answer 24

Green and Yellow stripes

Question 25

What voltage goes through the live wire?

Answer 25

230V

Question 26

What voltage goes throught the neutral and earth wire?

Answer 26

0V

Question 27

What does the live wire do?

Answer 27

Carries current to the appliance

Question 28

What does the neutral wire do?

Answer 28

Carries current away from the appliance

Question 29

What does the earth wire do?

Answer 29

Stops the exterior of the appliance becoming live

Question 30

What is power?

Answer 30

The rate at which energy is transferred or work is done

Question 31

What is efficiency?

Answer 31

The ratio of useful energy out to total energy in

Question 32

How do you increase the efficiency of an energy transfer?

Answer 32

Reduce the amount of waste energy

Question 33

What is the national grid?

Answer 33

A system of cables and transformers linking power stations to homes and businesses

Question 34

What does the power station do?

Answer 34

Transfers the energy supply into electrical energy

Question 35

What do step up transformers do?

Answer 35

Increase potential difference from the power station to the transmission cables

Question 36

What do transmission cables do?

Answer 36

Transfer the electricity

Question 37

What do step down transformers do?

Answer 37

Reduce the potential difference

Question 38

What happens when insulating materials are rubbed together?

Answer 38

They become electrically charged

Question 39

What does the friction do when two insulating materials are rubbed together?

Answer 39

Moves negatively charged electrons from one material to another

Question 40

What is an object with no conducting path referred to as?

Answer 40

Isolated object

Question 41

What happens as the charge of an isolated object increases?

Answer 41

The potential difference between the object and the earth increases

Question 42

What kind of force is an electro static force?

Answer 42

Non-contact

Question 43

What can electrostatic forces be?

Answer 43

Attraction or repulsion

Question 44

What happens when two objects have the same charge?

Answer 44

The repel

Question 45

What happens when two objects have a different charge?

Answer 45

They attract

Question 46

What does a charged object create?

Answer 46

A electric field around itself

Question 47

What does the strength of an electric field depend on?

Answer 47

The distance from the object The amount of charge