Y9 Science Exam

Question 1

An ammeter is used to measure

Answer 1

electric current.

Question 2

An electric current of 500 mA is equal to

Answer 2

0.500 A.

Question 3

A unit of electrical resistance is the

Answer 3

ohm.

Question 4

The voltage in an electric circuit is a measure

of

Answer 4

Voltage (V) is a measure of the pressure applied to electrons to make them move. It is a measure of the strength of the current in a circuit and is measured in volts

Question 5

Formula for Voltage

Answer 5

V = I x R (current x resistance)

Question 6

Formula for Amps

Answer 6

A = W/V

Question 7

Series Circuit

Answer 7

A series circuit has a much higher resistance so less current flows and less power
can be delivered to each device. Multiple devices in series cannot be independently switched on or off… one off, all off.

Question 8

Parallel Circuit

Answer 8

Parallel electrical circuits offer many advantages compared to series circuits.
• Full delivery of power to each device in the circuit. (e.g. brighter lights)
• Each device can be switched on or off independently.
• If one device “burns-out” all others continue to operate.