P4 + P5

Question 1

What is the job of an open switch?

Answer 1

Breaks the circuit to stop the electrical current.

Question 2

What is the job of a closed switch

Answer 2

Allows the electrical current

Question 3

What is the job of a cell?

Answer 3

A singular source of energy

Question 4

What is the job of a battery?

Answer 4

multiple sources of energy

Question 5

What is the job of a resistor?

Answer 5

Reduces electrical current

Question 6

What is the job of a bulb?

Answer 6

Emits light

Question 7

What is electricity?

Answer 7

the movement of electrons

Question 8

What are the 2 types of electrical circuits?

Answer 8

Series and parallel

Question 9

What is a series circuit?

Answer 9

it is connected with one pathway only (except a voltmeter)

Question 10

What is a parallel circuit?

Answer 10

Connected with 2 or more pathways.

Question 11

When drawing a circuit diagram, what way does the current flow?

Answer 11

From the positive side of the battery to the negative side.

Question 12

What is the definition of current?

Answer 12

it is the rate of flow of charge

Question 13

What is the equation for charge?

Answer 13

Q (charge) = I (current) x t (time)

Question 14

What are the units for charge?

Answer 14

C or coulombs

Question 15

What are the units for current?

Answer 15

Amps or A

Question 16

What are the units for time?

Answer 16

secons or s

Question 17

In a series circuit, the current is…

Answer 17

constant in all positions

Question 18

In a parallel circuit, current can …

Answer 18

change in different positions

Question 19

What is potential difference?

Answer 19

the difference in the amount of potential energy between 2 points.

Question 20

What is potential difference measured in?

Answer 20

Volts

Question 21

Why do electrons move?

Answer 21

because of electrostatic attration

Question 22

What is the equation for energy?

Answer 22

E=QxV

Question 23

What is the equation for resistance?

Answer 23

R (resistance) = I (current) / V (potential difference)

Question 24

What is resistance measured in?

Answer 24

Ohms or that weird symbol

Question 25

mA —> A ?

Answer 25

Divide by 1000

Question 26

mA <— A

Answer 26

X 1000

Question 27

How does static electricity work?

Answer 27

1. An object becomes charged by adding or removing electrons. 2. A potential difference occurs between the 2 objects. 3. The potential difference causes current to flow between the surface until there’s no longer a potential difference.

Question 28

What are the dangers of static electricity?

Answer 28

The sparks are enough to set a flammable material alight and cause a fire.

Question 29

What is alternating current (AC)?

Answer 29

If the current constantly changes direction. Light flickering quickly

Question 30

Mains electricity is an __ supply, with the UK mains supply being about ___v and having a frequency of __ Hz.

Answer 30

AC 230v 50Hz

Question 31

What’s the graph for AC?

Answer 31

A wavy line

Question 32

What’s the graph for DC?

Answer 32

A straight line across

Question 33

What is direct current (DC)?

Answer 33

If the current flows in only one direction.

Question 34

What has a DC supply?

Answer 34

Batteries and cells

Question 35

How much does a typical battery supply of DC?

Answer 35

1.5v

Question 36

What is the function of live wire?

Answer 36

Carries current around the circuit. Current goes into device.

Question 37

What is the function of the neutral wire?

Answer 37

Carries current round the circuit away from device.

Question 38

What is the function of the neutral wire?

Answer 38

Safety wire. Used to earth appliance when something goes wrong.

Question 39

What is the colour for the live wire?

Answer 39

Brown

Question 40

What’s the colour for the neutral wire?

Answer 40

Blue

Question 41

What’s the colour for the earth wire?

Answer 41

Green/yellow

Question 42

What do fuses prevent?

Answer 42

Fires

Question 43

What does earth wires protect?

Answer 43

Electrocution

Question 44

What are the 3 safety features appliances have?

Answer 44

The fuse, earth wire, switch

Question 45

How and why does the fuse melt?

Answer 45

If a large current will flow through the fuse causing it to melt. This breaks the circuit and protect the appliance and user from harm.

Question 46

What is the calculation for fuse?

Answer 46

Power = current x potential difference

Question 47

What are the 8 energy stores?

Answer 47

Chemical Thermal Elastic Magnetic Gravitational potential Electrostatic Kinetic Nuclear

Question 48

What is the equation for efficiency?

Answer 48

Useful energy / total energy (x 100 if asking for percentage)

Question 49

How do you increase efficiency?

Answer 49

To increase efficiency of a machine, the wasted energy transfers need TK be reduced with no change to the useful transfers.