T2 P1: Electricity

Question 1

What does a circuit need for a charge to flow?

Answer 1

-Switches Closed
-Potential difference (from a battery or a cell)

Question 2

What is current?

Answer 2

A flow of electrical charge

Question 3

What equation can current, potential difference and resistance all be calculated in?

Answer 3

V= IR

Question 4

What is potential difference measured in?

Answer 4

Volts (v)

Question 5

What is current measured in?

Answer 5

Amperes (A)

Question 6

What is resistance measured in?

Answer 6

Ohms (Omega symbol)

Question 7

What 5 things can resistance change?

Answer 7

Current
Temperature
Light
Length
Voltage

Question 8

What does a current do in a series circuit?

Answer 8

Follows a single path so the current is the same everywhere

Question 9

What does a current do in a parallel circuit?

Answer 9

it splits into multiple paths

Question 10

What is the frequency of the UK’s Domestic Electric Supply?

Answer 10

50Hz

Question 11

How many volts is the UK’s Domestic Electricity Supply?

Answer 11

230 V

Question 12

What sort of supply is mains electricity?

Answer 12

An AC Supply.

Question 13

What sort of current does AC have?

Answer 13

Alternating Current

Question 14

What sort of current does a DC have?

Answer 14

Direct Current (which moves in 1D only)

Question 15

What are the 3 wires in a plug?

Answer 15

Live wire (Brown)
Neutral wire (Blue)
Earth wire (Green and Yellow)

Question 16

What is the voltage of the Live (Brown) wire?

Answer 16

230 V

Question 17

What is the purpose of the live wire?

Answer 17

To carry the alternating potential difference from the supply.

Question 18

What is the voltage of the neutral (blue) wire?

Answer 18

0 V

Question 19

What is the purpose of the Neutral wire?

Answer 19

To complete the circuit

Question 20

What is the voltage of the Earth (yellow and green) wire?

Answer 20

0 V, unless there is a fault with the rest of the plug

Question 21

What is the purpose of an Earth Wire?

Answer 21

To stop the appliance becoming live.

Question 22

Power is the…

Answer 22

… energy transferred per second

Question 23

What is power DIRECTLY proportional to?

Answer 23

Current
+
Voltage

Question 24

What is power loss proportional to?

Answer 24

Resistance
+
Square of the current

Question 25

What is electric current?

Answer 25

The flow (movement) of electric charges.

Question 26

What 2 things does an electric charge need to flow?

Answer 26

A source of potential difference and a closed circuit.

Question 27

What is electric current measured in?

Answer 27

Amperes (A)

Question 28

True or False: A current has the same value at every point in a single closed loop.

Answer 28

True.

Question 29

How do you calculate current?

Answer 29

Charge/time

Question 30

What is current?

Answer 30

The movement of electrons.

Question 31

What is charge measured in?

Answer 31

Coulombs (C)

Question 32

What is an electrical conductor?

Answer 32

A material that allows electric currents to pass through it.

Question 33

True or false: all metals are electrical conductors.

Answer 33

True

Question 34

What is an electrical insulator?

Answer 34

A material that doesn’t allow electric currents to pass through it.

Question 35

Name 2 examples of electrical insulators.

Answer 35

Plastic and glass

Question 36

An electric insulator has no…

Answer 36

…free electrons

Question 37

An electrical conductor has lots of charges that are…

Answer 37

…free to move

Question 38

What charges are free to move in metals?

Answer 38

Electrons

Question 39

Is mercury and electrical insulator?

Answer 39

No

Question 40

What is potential difference?

Answer 40

The difference in the amount of energy that charge carriers have between two points in a circuit.

Question 41

What is potential difference also called?

Answer 41

Voltage

Question 42

What is potential difference measured in?

Answer 42

Volts

Question 43

What do we use to measure the potential difference?

Answer 43

Voltmeter.

Question 44

What does an ammeter?

Answer 44

The flow of current that passes through it.

Question 45

What to ammeters have to be connected in?

Answer 45

Series (in the same loop of the circuit)