Science, electrical circuits

Question 1

Ammeter

Answer 1

A device used to measure the current at a single point in a circuit

An ammeter gives a reading in amperes (A) that can be positive or negative, depending on which direction electrons flow.

Question 2

Ampere

Answer 2

The standard unit of electrical current

Amperes or amps have the symbol A. A hair dryer requires about 14 A of 12 volt power to run.

Question 3

battery

Answer 3

A component that stores chemical energy to be used as a power source

When battery terminals are connected by a wire, chemical energy is transferred to electrons and causes them to flow.

Question 4

circuit

Answer 4

A pathway for electricity to flow around

A circuit must include a source of electricity, like a battery, and something to conduct electricity, like a wire.

Question 5

circuit diagram

Answer 5

A model of the components of a circuit and how they are connected

Circuit diagrams use special symbols for the components and ruled lines to show their connections.

Question 6

Closed circuit

Answer 6

A complete pathway that allows electrical current to flow

A closed circuit has no gaps or open switches. Electricity can flow.

Question 7

Component

Answer 7

Part of an electrical circuit

Components of electrical circuits include batteries, wires and lamps.

Question 8

electrical current

Answer 8

The flow of electrons through a circuit

Electrons flow along a wire from an area of negative charge to an area of positive charge.

Question 9

electron

Answer 9

A very small subatomic particle with negative charge

Electrons furthest from the nucleus of an atom can be forced to move from one atom to another.

Question 10

Ohms law

Answer 10

The relationship between current, voltage and resistance

Electrical current is directly proportional to voltage and inversely proportional to resistance.

Question 11

resistance

Answer 11

A material’s opposition to the flow of electrical current

The higher the resistance of a component, the harder it is for electrons to flow and the more energy they lose as heat.

Question 12

resistor

Answer 12

A component designed to lower the current passing through a circuit

A resistor is made from a material with high resistance to slow down the movement of electrons.

Question 13

voltage

Answer 13

The amount of energy or ‘push’ given to electrons moving in a circuit

The higher the voltage supplied to a circuit, the bigger the ‘push’ the electrons receive.