Static And Current Electricity

Question 1

Conductors

Answer 1

Are substances which allow electric current to flow through them freely

Question 2

Insulators

Answer 2

Are substances which do not allow electric current to flow through them

Question 3

Closed circuit

Answer 3

Is needed for the current to flow, if there is a break the current won’t flow

Question 4

Energy provided

Answer 4

By battery or power pack, needed to move the current around the circuit

Question 5

Battery pumps electrons

Answer 5

from its negative end around the circuit

Question 6

Electrons are attracted

Answer 6

Back to the positive end of battery

Question 7

Potential difference

Answer 7

The difference in electrical pressure between the positive and negative ends of battery / power pack

Question 8

Whenever there is a potential difference

Answer 8

Electricity will flow

Question 9

This potential difference is known as

Answer 9

Voltage and is measured in volts

Question 10

Resistance

Answer 10

Is the opposition to the flow of electrons the unit is ohm and it is measured using an ohmmeter

Question 11

If a resistor is placed in an electric circuit

Answer 11

It will slow down the flow of electrons

Question 12

Electric current

Answer 12

Is a flow of electric charge

Question 13

Ac

Answer 13

Alternating current changes very quickly many times a second

Question 14

Dc

Answer 14

Direct current goes in one direction only eg. The current from battery

Question 15

Live wire

Answer 15

Is brown and carries most electricity it is connected to the plugs fuse is on the right side

Question 16

Neutral wire

Answer 16

Blue connected to Left hand side

Question 17

Earth wire

Answer 17

Safety wire, no electricity flows in the earth wire unless the appliance it is attached because live eg toaster in this case the earth wire would carry the current to the earth instead of you electrocuting yourself should you touch the toaster

Question 18

Watt

Answer 18

Unit of electrical power

Question 19

Esb

Answer 19

Charges a free for the number of kilowatts

Question 20

Esb unit

Answer 20

Is the kilowatt hour (kWh)

Question 21

A kilowatt hour

Answer 21

Is the electrical emergent used by a 1kW appliance running for the 1 hour

Question 22

Heating effect

Answer 22

Boil water in kettle, immersion heater, electric cooker and fuse in plug

Question 23

Chemical effect

Answer 23

Electroplating cheap metal with more expensive metal eg. Silver electrolysis (splitting) of water mobile phone battery

Question 24

Magnetic effect

Answer 24

Electromagnet made with a wire wrapped around a nail, electric motor, speakers. Circuit breaker in fuse board

Question 25

Electronics

Answer 25

Is the careful and exact control of tiny amounts of electric current

Question 26

Is a component that will allow current to flow in one direction only

Answer 26

Diode

Question 27

Forward biased

Answer 27

If the positive end of a battery is connected to the positive end of diode the Current can flow

Question 28

Reverse biased

Answer 28

If the positive end of the battery is connected to the negative end of the diode no electricity can flow

Question 29

Diode current can be used

Answer 29

To change alternating current into direct current

Question 30

Electronic devices such as radios tape recorders and calculators

Answer 30

Need low voltage direct current

Question 31

They work off the main esb supply which is a high voltage alternating current

Answer 31

Because they have an adaptor built into them

Question 32

The adapter has a transformer which reduces the voltage and a diode

Answer 32

Which changes the current from ac to dc

Question 33

Light emitting diode

Answer 33

Is a diode that gives out light when a current flows through it

Question 34

Current will only flow when led

Answer 34

Is forward biased

Question 35

Leds use only tiny currents

Answer 35

A resistor must be connected in series with it

Question 36

Leds are useful as they are

Answer 36

Cheap, reliable and long lasting and use far less current than other light bulbs

Question 37

Light dependent resistor

Answer 37

Is a resistor whose resistance depends on light

Question 38

When light falls on an ldr

Answer 38

it's resistance decreases, this low resistance will allow a current through the circuit