Energy and Potential Difference in Circuits

Question 1

Define electric current

Answer 1

Is the rate of flow of charge

Question 2

In a wire, which direction do the electrons flow

Answer 2

Negative to positive

Question 3

What is convectional current

Answer 3

Flowing around the circuit from the positive to negative terminal.

Question 4

What does current mean

Answer 4

flowing from positive to negative per second

Question 5

What is charge measured in

Answer 5

Coulombs, (C)

Question 6

What is current measured in

Answer 6

Amps (A)

Question 7

In the equation “charge, current, time” What does Q and I stand for in the triangle

Answer 7

Q = Charge
I = Current

Question 8

Give the equation to find out the charge from the current and time

Answer 8

Charge = Current x Time

Question 9

What is time always measured in

Answer 9

Seconds

Question 10

What charge passes if 4A flows for 20 seconds

Answer 10

CHARGE = CURRENT X TIME
Current = 4
Time = 20
4 x 20 = 80
Charge = 80C

Question 11

What is the difference between a parallel and Series circuit

Answer 11

Parallel splits

Series is a continues line.

Question 12

What does an Ammeter measure

Answer 12

Current

Question 13

Why do you start the variable resistor to maximum at the start of the experiment

Answer 13

So that the equipment doesn’t break straight away.

Question 14

The….current in a parallel circuit is equal to the sum of the currents in the …….sections of the circuit

Answer 14

Total

Parallel

Question 15

What is used to measure volts

Answer 15

A voltmeter

Question 16

In series, current is……everywhere

Answer 16

Equal

Question 17

In parallel, Total current =………..

Answer 17

Amp 1 + Amp 2 + Amp 3

Question 18

Define resistance

Answer 18

The ratio of the voltage, to the current

Question 19

Give the equation that links voltage, current and resistance

Answer 19

Voltage = Current x resistance

Question 20

What is resistance measured in

Answer 20

Ohms, (Ω)

Question 21

Calculate the voltage required to cause a current of 3A to flow through a resistance of 5 Ω

Answer 21

Current = 3
Resistance = 5
3 x 5 = 15
Voltage = 15V

Question 22

What does m and k mean

Answer 22

M = ÷ 1000
K = x 1000

Question 23

When a……flows through a component that has………, the component….up and it’s…….increases

Answer 23

Current
Resistance
Heats
Temperature

Question 24

Describe the shape of the graph for the resistance in a wire

Answer 24

Resistance is constant

Line is perpendicular

Question 25

Describe the shape of the graph for the resistance in a bulb

Answer 25

The line goes perpendicular up to a point, but then levels off. The resistance increases due to heat.

Question 26

Describe the shape of the graph for the resistance in a diode

Answer 26

The line remains very low and flat before suddenly shooting upward almost vertically.

Question 27

As the length of wire……………the more the resistance…… up to point where the resistance……………………..

Answer 27

Increases
Increases
Levels off

Question 28

What do LED’s do

Answer 28

They emit light when a current flows through them.

Question 29

What does power mean

Answer 29

Measures the rate at which electrical energy is transferred, (usually turned into heat)

Question 30

What is power measured in

Answer 30

Watts (W)

Question 31

Give the equation that links power, work done (energy) and time

Answer 31

Work done = Power x Time

Question 32

What is work done measured in

Answer 32

Joules

Question 33

Give the equation that links power, current and voltage

Answer 33

Power = Current x Voltage