Electricity - Section 1

Question 1

What is static electricity?

Answer 1

A stationary electric charge built up on an insulating material

Question 2

What are the three laws of electrical charges?

Answer 2

Opposite charges attract
Like charges repel
Charged objects can be attracted to neutral objects

Question 3

What is a Van de Graaff Generator?

Answer 3

A machine that uses friction to produce a build up of static electricity

Question 4

For an electrical current to flow continuously, what two requirements must be met?

Answer 4

There must be an energy source

It must have a complete path or circuit for the charged particles to flow through

Question 5

What are conductors?

Answer 5

Materials which electricity can flow through easily

Question 6

What is an insulator?

Answer 6

This is a material that electrical current does not flow through easily

Insulating materials are often used as a protective cover on the conductor

Question 7

What is circuit?

Answer 7

A path that controls the flow of electricity

Question 8

What does a circuit usually include?

Answer 8

A conductor
An energy source
A device that converts the electrical energy to another form of energy (also called a load)

Question 9

What is an ampere?

Answer 9

Unit used to measure the rate at which an electrical current flows
Abbreviated unit is A

Question 10

What is an ammeter?

Answer 10

Measures electrical current in amperes, or milliAmps

Question 11

What is voltage?

Answer 11

A measure of how much electrical energy each charged particle carries, in volts

Question 12

What is a voltmeter?

Answer 12

Measured the charge in the potential energy of electrical charge compared to its potential energy
No volts or millivolts

Question 13

What is resistance?

Answer 13

A measure of how difficult it is for electrons to flow through a substance
Measured in ohms
Symbol is the Greek letter Omega

Question 14

What is an Ohmmeter?

Answer 14

Measures electrical resistance, in ohms

Question 15

What are fuses?

Answer 15

Fuses contain a thin piece of special metal that will melt if the electricity going through it is too high. These must be replaced once that metal has melted

Question 16

What are circuit breakers?

Answer 16

Have a special wire that heats up, but doesn’t melt. The hot wire triggers a spring that will turn off the switch with particular circuit or path. This can be switched back on once the wire has cooled

Question 17

What is a cell?

Answer 17

A device that converts chemical energy into electrical energy

Question 18

What are the two types of cells?

Answer 18

Dry cells

Wet cells

Question 19

What are dry cells?

Answer 19

The chemicals in dry cells are in a paste

They are sealed so that they can be used in any position without the chemical leaking out

Question 20

What are wet cells?

Answer 20

The chemicals in wet cells are liquid

The electrolyte is liquid, usually an acid

Question 21

What are the advantages and disadvantages to set cells?

Answer 21

An advantage is that they are generally cheaper and easier to make

A disadvantage is that they can easily spill, and the acid is highly corrosive

Question 22

What are primary cells?

Answer 22

These are cells that can only produce electricity until their chemicals have fully reacted

After this happens they must be thrown away

Question 23

What are secondary cells?

Answer 23

These are rechargeable cells

Once the reactants have been used up, electricity can be run back through them using an external electrical source

Question 24

What are batteries?

Answer 24

Two or more cells joined together to produce an electric current

Question 25

What is electroplating?

Answer 25

When a cheap metal is used and then is “plated” with a more expensive metal