Electricity

Question 1

For electrical charge to flow what must be ensured

Answer 1

The circuit must be closed and must include potential difference

Question 2

What is electric current

Answer 2

A flow of electrical charge

Question 3

What is the letter for charge flow

Answer 3

Q

Question 4

What is charge flow measure in

Answer 4

Columbus (C)

Question 5

What is the letter for current

Answer 5

I

Question 6

What is current measured in

Answer 6

Amps (A)

Question 7

What does a current have the same value at

Answer 7

Any point in a single closed loop

Question 8

What does the current through a component depend on

Answer 8

On both the resistor of the component and the potential difference across the component

Question 9

The grater the resistance is of the component the what

Answer 9

The smaller the current for a given potential difference across the component

Question 10

What is the equation for current ,potential offence and resistance

Answer 10

Potential difference =
current x resistance

Question 11

What is the letter for potential difference

Answer 11

V

Question 12

What is potential difference measured in

Answer 12

Volts (V)

Question 13

What is the letter for resistance

Answer 13

R

Question 14

What is resistance measured in

Answer 14

Ohms (horse shoe thingy)

Question 15

Describe the current thro a ohmic conductor

Answer 15

It’s directly proportional to the potential difference across the resistor

Question 16

Describe the resistance of compounds such as lamps ,diodes ,thermistors and LDRs

Answer 16

The resistance is not constant as it changes with the current through the component

Question 17

What did the resistance if a filament lamp inc

Answer 17

Teh resistance of a filament lamp Increases as the temperature of the filament increases

Question 18

How does the current in a diode flow

Answer 18

In one direction only

Question 19

Describe the diodes residence

Answer 19

The diode has a very high resistance in the reverse direction

Question 20

As the residence in a thermistor dec what happens

Answer 20

The temp inc

Question 21

What happens as the resistance of an LDR as it dec

Answer 21

The light intensity inc

Question 22

Two types of circuits

Answer 22

Series and parallel

Question 23

Describe components connected in a series circuit

Answer 23

-there is the same current through each component
-the total potential difference of the power supply is shared between components
-the total resistance of two components is the sum of the resistance of each component

Question 24

What is the equation for the total resistance of two components

Answer 24

R total =R1+R2

Question 25

Describe components connected in a parallel circuit

Answer 25

-the potential difference across the component is the same -the total current through the whole circuit is the sum of the currents through the separate components -the total resistance of two resistors is less than the resistance of the smallest individual resistor

Question 26

What colour is the live wire

Answer 26

Brown

Question 27

What colour is the neutral wire

Answer 27

Blue

Question 28

What colour is the earth wire

Answer 28

Green and yellow stripes

Question 29

What does the live wire carry

Answer 29

The alternating potential difference from the supply

Question 30

What does the neutral wire do

Answer 30

It Completes the circuit

Question 31

What is the earth wire

Answer 31

It’s a safety wire to stop the appliance form becomibg live

Question 32

What is the potential difference between the live and earth wire

Answer 32

0v - 230v

Question 33

What is the neutral wires potential difference

Answer 33

It at or near 0v

Question 34

When does the earth wire carry potential difference

Answer 34

When there is a fault

Question 35

What is the two equations for power

Answer 35

Power= potential diff x current Power= (current)2 x resistance

Question 36

What is the letter for power

Answer 36

P

Question 37

What is power measured in

Answer 37

Watts (w)

Question 38

What does the amount of energy an appliance transfer depend I.

Answer 38

How long the appliance is switched on for and the power of the appliance

Question 39

When is work done

Answer 39

When charge flows in a circuit

Question 40

What are the two equations for energy

Answer 40

Energy transf = power x time Energy transf = charge flow x potential diff

Question 41

What is the national grid system

Answer 41

A system of cables and transformers linking power stations to consumers

Question 42

Where is electrical power transferred form

Answer 42

Form power stations to consumers using the national grid

Question 43

What are set up transformers used for

Answer 43

To inc the potential difference form the power station to the transmission cables

Question 44

What are step down tranformers used to do

Answer 44

To decrease to a much lower value , the potential difference for domestic use