Electricity

Question 1

What is meant by a complete circuit?

Answer 1

In order for a circuit to work it has to be complete, the current has to flow from one side to the other with no gaps

Question 2

What is a series circuit?

Answer 2

In a series circuit the electrical current flows round in 1 path through each component

Question 3

What is a parallel circuit?

Answer 3

In parallel the electrical current is able to branch off to reach each component on the board

Question 4

What happens when more bulbs are added to a series circuit?

Answer 4

When more bulbs are added upin series the light given off gets dimmer (if the bulbs are identical the light given off will be the same)

Question 5

What happens when 1 bulb breaks in series?

Answer 5

When 1 bulb breaks, the whole circuit is broken it becomes incomplete and the electrical current can’t flow round the circuit

Question 6

What happens when more bulbs are added in parallel?

Answer 6

When more bulb are added in parallel the light given off will stay the same, there should be no change in brightness

Question 7

What happens when 1 bulb breaks in parallel?

Answer 7

When 1 bulb breaks the rest will remain on as in parallel the current can branch off and reach a,l bulbs at the same time keeping a complete circuit

Question 8

-l I- - -l I-

Answer 8

Battery

Question 9

-lI-

Answer 9

Cell

Question 10

-o/ o-

Answer 10

Switch

Question 11

-O-

Answer 11

Bulb

Question 12

What is an electrical conductor?

Answer 12

An electrical conductor should allow an electric current to flow through it easily

Question 13

Give 3 examples of an conductor?

Answer 13

Copper, brass and carbon (graphite)

Question 14

What is an electrical insulator?

Answer 14

An electrical insulator should not allow an electrical current to flow through it at all

Question 15

Give 3 examples of an insulator

Answer 15

Glass, rubber and silicon

Question 16

Draw a diagram of a circuit to show the correct positions of an ammeter and a voltmeter

Answer 16

——lI- - -lI——
l l l= walls
A l A= ammeter
l l V= voltmeter
—O——O—— O= bulb
l l
V

Question 17

Describe electrical current in terms of movement and charges around a circuit

Answer 17

An electrical current is the flow of electrons. Electrons are negatively charged meaning they move round the board from the negative charge in a battery

Question 18

What is the rule for current in series?

Answer 18

In series the current is the same at all positions round the board

Question 19

What is the rule for voltage in series?

Answer 19

The sum of voltages across components in series is equal to the voltage drawn from the supply

Question 20

What is the rule for current parallel?

Answer 20

In parallel branches is equal to the current drawn from the supply

Question 21

What is the rule for voltage in parallel?

Answer 21

The voltage across components in parallel is the same for each component

Question 22

What is the function of switches in series?

Answer 22

If there is more than one switch in series, all of them need to be pressed down in order to let the current flow and complete the circuit

Question 23

What is the function of switches in parallel?

Answer 23

If there is more than one switch in a parallel circuit one (or any) can be closed in order to complete the circuit as the current can branch if and reach other components

Question 24

What is electrical resistance?

Answer 24

Electrical resistance is the ability of an object to reduce (or oppose) the flow of a current

Question 25

What is the link between voltage and current for a resistor?

Answer 25

Voltage and current are directly proportional for a resistor.
A graph of V versus I will always be a straight line through the origin

Question 26

Define R=V/I

Answer 26

Resistance (Ohms)= Voltage (V)/ Current (I)

Question 27

What is the equation to find out the voltage?

Answer 27

V=IR