Chapter 5

Question 1

What is an electric circuit?

Answer 1

A closed loop that provides a path for the transfer of electrical energy

Question 2

Whata does a circuit require?

Answer 2

A source of electricity, a lode / component (converts electrical energy into other forms of energy) and wires

Question 3

What is a circuit diagram?

Answer 3

A visual representation of the arrangement of the different parts of a circuit

Question 4

What is an electrical current?

Answer 4

A measure of the rate of flow of charges passing through a point along the wire

Question 5

What is electrical current measured in?

Answer 5

Amps

Question 6

What is voltage?

Answer 6

A measure of the amount of energy supplied to the charges by the power source

Question 7

What is voltage measured in?

Answer 7

Volts

Question 8

What is resistance?

Answer 8

A measure of how difficult it is for an electric current to flow through a material or component

Question 9

What is resistance measured by?

What device?

Answer 9

A multimeter

Question 10

What is the units for resistance?

Answer 10

Ohms

Question 11

What are conductors?

Answer 11

Materials that have very low resistance and allow electric current to pass through them easily, such as metals like sopper

Question 12

What are insulators?

Answer 12

Materials that have high resistance and prevent electric current to pass through easily

Question 13

What is Ohm’s law?

Answer 13

Resistance = Voltage / Current

Question 14

What is a series circuit?

Answer 14

A circuit where all the components are connected one after another to form a single loop. The voltage is shared between each component

Question 15

What are the good things about series circuits?

Answer 15

Easy to build, less materials

Question 16

What are the bad things about series circuit?

Answer 16

The globes cannot be controlled individually by a switch, if any of the globes break then current stops flowing and adding more globes reduces their brightness, as the voltage splits.

Question 17

What is a parallel circuit?

Answer 17

Where there are multiple paths for the current to flow through. Have the same voltage because the current is split between them.

Question 18

What are the good things about parallel circuits?

Answer 18

Each branch can have its own switch, if any of the globes break, current still flows through the other pathways and adding extra globes do not reduce the brightness.

Question 19

What are the bad things about parallel circuits?

Answer 19

More difficult to build, more materials the current divides

Question 20

What is a combination circuit?

Answer 20

A mix of both types of circuits

Question 21

What is the standard voltage in houses?

Answer 21

240 V

Question 22

What do powerpoints have?

Answer 22

A third wire (earth wire) that connects the powerpoint to the earth beneath, allowing stray current to flow there instead of passing through you.

Question 23

What is a transformer?

Answer 23

A device used to drop the voltage of a power point

Question 24

What is voltage drop?

Answer 24

Where electrons lose energy as they pass through a component

Question 25

Properties of copper

Answer 25

Very low resistance, and relatively cheap

Question 26

Properties of aluminium

Answer 26

Like copper, but lighter

Question 27

Examples of insulators

Answer 27

Rubber, plastic, wood and glass

Question 28

Contents of a household powerpoint

Answer 28

Active wire Neutral wire Earth wire

Question 29

What does the active wire do?

Answer 29

Carries the current to the powerpoint. It is brown

Question 30

What does the neutral wire do?

Answer 30

Carries the current away from it. It is blue

Question 31

What is a fuse?

Answer 31

A wire that melts if too much current is flowing through it

Question 32

What is a circuit breaker?

Answer 32

A switch that is activated by a higher than normal current. When this happens, it breaks the circuit

Question 33

What are batteries made of and how do they produce an electrical current?

Answer 33

Electrochemical cells Create an electric current from a chemical reaction

Question 34

What do photovoltaic cells do?

Answer 34

Convert solar energy into electrical energy

Question 35

How do photovoltaic work?

Answer 35

The energy from the sunlight knocks electrons off semiconducting silicon crystals within the cell and form an electric current

Question 36

What is a turbine?

Answer 36

A large generator that creates current by spinning its magnet within a fixed set of coils

Question 37

How is a turbine spun?

Answer 37

Wind, moving water, or steam

Question 38

Direct current

Answer 38

Electrons move in one direction and loses energy over long distances

Question 39

Alternating current

Answer 39

Electrons change directions and can be transmitted over long distances using transformers