Physics - Electricity

Question 1

What does a cell do in a circuit

Answer 1

pushes electrons around the complete circuit

Question 2

What does a switch do in a circuit

Answer 2

enables the current in a circuit to be switched on or off

Question 3

What does a bulb (indicator) do in a circuit

Answer 3

designed to emit light as a signal when a current passes through it.

Question 4

What does a diode do in a circuit?

Answer 4

allows current to move in only one direction

Question 5

What does a light-emitting diode do in a circuit

Answer 5

emits light when a current passes through it

Question 6

What does an ammeter do in a circuit

Answer 6

used to measure electrical current

Question 7

What does a fixed resistor do in a circuit

Answer 7

Limits the current in a circuit

Question 8

What does a variable resistor do in a circuit

Answer 8

allows the current to be varied

Question 9

What does a fuse do in a circuit

Answer 9

designed to melt and break the circuit if the current going through it is greater than its limit.

Question 10

What does a voltmeter do in a circuit

Answer 10

used to measure voltage

Question 11

What is the relationship between electric charge and electric current

Answer 11

its the same e.g. 1 charge flow (coulombs) = 1 electric current (amps)

Question 12

What is potential difference

Answer 12

energy transfered to a component or the work done on it by each coulomb of charge that passes through it.

Question 13

What happens in a series circuit with the potential difference

Answer 13

split/ shared between components

Question 14

What happens in a parallel circuit with the potential difference

Answer 14

The potential difference accross each component is the same

Question 15

What is the resistance, and what is the unit

Answer 15

Potential difference required to drive a current through a component and the unit is ohms

Question 16

What is the equation for resistance

Answer 16

Resistance = potential difference
current