Electricity

Question 1

What are the two types of electricity?

Answer 1

Static electricity and current.

Question 2

Define static and give an example.

Answer 2

Electrical charge on an insulator. Produced by friction.
Example: Lightening/balloons.

Question 3

Give two differences between static and current:

Answer 3

STATIC:
-Doesn’t move.
-Build up of electrons.
-Builds up on insulators.
CURRENT:
-Moves.
-Flow of electrons.
-Flows through conductors.

Question 4

Define current:

Answer 4

The flow of electrical charge.

Question 5

What is the difference between a conductor and an insulator?

Answer 5

A conductor allows electricity and heat to pass.
An insulator doesn’t allow heat or electricity to pass.

Question 6

Define earthing:

Answer 6

When an object or a building is connected to the ground by a conductor, current and charge will flow to earth.

Question 7

Why is a circuit important?

Answer 7

A circuit is required for current to flow.

Question 8

What are the differences between a series and a parallel circuit?

Answer 8

Series:
- Each bulb is on the same circuit.
- The voltage of the battery is shared between the bulbs.
- If 1 bulb goes out, they all go out.
Parallel:
- Each bulb has it’s own circuit.
- Each bulb receives separate voltage from the battery.
- If 1 bulb goes out the other(s) remain lit.

Question 9

Match the symbols:
A: Voltage. 1. I
B: Current. 2. R
C: Resistance. 3. V

Answer 9

A,3
B,1
C,2

Question 10

What is
A. Voltage measured in?
B. Current measured in?
C. Resistance measured in?

Answer 10

A. Volts (V)
B. Amps (A)
C. Ohms (Ω)

Question 11

The current through a lamp connected across 100V is 5A when the lamp is on. What is its resistance?

Answer 11

R= V/I
R=100/5
R=20Ω

Question 12

A motor with an operating resistance of 30Ω is connected to a voltage source. The current is 4A. Fond the voltage:

Answer 12

V=I×R
V=4×30
V=120V