Electricity

Question 1

Who made the first battery and in what year?

Answer 1

Volta, 1800

Question 2

Name 3 other discoveries made using electricity and name the person who discovered it.

Answer 2

1) 1876- Telephone (Bell)
2) 1877- Record player (Edison)
3) 1879- Light (Edison)

Question 3

What are conductors?

Answer 3

Conductors are materials that electricity (electrons) can flow easily through e.g. electrical wires are made of copper metal.

Question 4

What are insulators?

Answer 4

Insulators are materials that prevent electricity flowing through them.

Question 5

Give 2 examples of insulators and one example of where they are used.

Answer 5

Insulators:
1) plastic
2) rubber
Plastic is wrapped around electrical wires.

Question 6

What is needed for electricity to flow?

Answer 6

A complete circuit

Question 7

What is the rate at which electricity is flowing called, what is it measured in and what meter is used to meausure it?

Answer 7

Current
Measure in Amperes (Amps)
Measures using a meter called an Ammeter

Question 8

What is voltage and give an example.

Answer 8

Voltage is the rate at which the parts of a circuit converts the energy of electricity (electrons) to different forms of energy, e.g. the rate at which a light converts electrical energy into light.

Question 9

What is voltage (potential difference) measured in and using what meter?

Answer 9

Volts

Voltmeter

Question 10

What is resistance?

Answer 10

A measure of how easy it is for electricity to flow through wires.

Question 11

Do thin wires have a higher or lower resistance then thick wires?

Answer 11

Higher

Question 12

The longer the wire is the higher or lower the resistance?

Answer 12

Higher

Question 13

What units is resistance measured in?

Answer 13

Ohms

Question 14

What is Ohm’s Law?

Answer 14

Ohm’s Law is a mathematical law which relates current (I), voltage (V) and resistance (R) in a circuit.

Question 15

State the formula for Ohm’s Law.

Answer 15

Voltage= Current x Resistance 
V= I x R, or the Law can be written as
I= V/R
R= V/I

Question 16

The amount of current flowing is equivalent to…

Answer 16

The voltage applied

Question 17

If the voltage is doubled then the current will…

Answer 17

double

Question 18

What is a fuse and what are they used for?

Answer 18

A fuse contains a metal which will melt if too much electricity (current) flows through the wire. Fuses are used to protect circuits and prevent electrical fires.

Question 19

What is a series circuit?

Answer 19

A series circuit is a circuit that only has one path for electricity to flow. For example, (refer to science revision booklet diagram) each globe is only half as bright as if one globe was used. If one globe blows, so will the other.

Question 20

What is a parallel circuit?

Answer 20

A parallel circuit is a circuit that has more then one resistor and has multiple paths for electricity to flow.
(Look at diagram)

Question 21

What is power a measure of?

Answer 21

how rapidly an electrical appliance changed electrical energy into other forms of energy.

Question 22

What is power measured in?

Answer 22

Watts

Question 23

What is the equation for power?

Answer 23

Power= Voltage x Current
P= V x C

Question 24

What is a circuit diagram?

Answer 24

A circuit diagram is a map of a circuit using standard symbols to represent different components.

Question 25

What is electro- magnetism?

Answer 25

A magnetic field surrounding a wire carrying an electric current.

Question 26

Give two examples of objects that use electro- magnetism?

Answer 26

• Bells

- Circuit breakers

Question 27

What is direct current (DC)?

Answer 27

Electricity that flows one direction through the circuit. Batteries produce direct current.

Question 28

What is alternating current (AC)?

Answer 28

The direction of current flow through the circuit is changed 10 times per second (50 Hertz).