4.1 Current And Charge

Question 1

What is an electric current

Answer 1

A flow of charge

Question 2

Describe how electrons move in metal

Answer 2

Move freely between the positively charged metal ions

Question 3

What does the size of electric current mean

Answer 3

The rate of flow of electric charge

Question 4

What is charge flow measured in

Answer 4

Coulombs (C)

Question 5

What is electric current measured in?

Answer 5

Amps (A)

Question 6

Charge flow calculation

Answer 6

Current x time taken (seconds)

Question 7

What is the cell needed for

Answer 7

Push electrons around a complete circuit

Question 8

What is a switch needed for

Answer 8

Enables current to be switched on and off

Question 9

What is the bulb needed for

Answer 9

Designed to emit light and show current passing through

Question 10

What is a diode used for

Answer 10

Allow current through in one direction only

Question 11

What is a light emitting diode used for

Answer 11

Emits light when a current passes through

Question 12

What is a fixed resistor used for

Answer 12

Limits current in a circuit

Question 13

What is a variable resistor used for

Answer 13

Allows current to be varied

Question 14

What is the fuse used for

Answer 14

Melt, breaking the circuit to show the current is greater

Question 15

What is a heater used for

Answer 15

Designed to transfer energy from electric current to surroundings

Question 16

What is a voltmeter used for

Answer 16

To measure potential difference

Question 17

What is a battery

Answer 17

Two or more cells connected together

Question 18

What is an ammeter used for

Answer 18

to measure electric current

Question 19

Why do we still use the rule of conventional current?

Answer 19

Because charge-carrying particles in different substances can be positive or negative