Static and Current Electricity

Question 1

Polythene rod

Answer 1

Gains electrons

Question 2

Perspex rod

Answer 2

Loses electrons

Question 3

Earthing

Answer 3

Occurs when a charged object loses its charge to the earth through a conductor

Question 4

Static electricity

Answer 4

A build up of electric charge that can occur on good insulators e.g polythene and perspex rods

Question 5

Electric current

Answer 5

Is a flow of electric charge (electrons)

Question 6

Conductors

Answer 6

Substances which allow electric current to flow through them freely

Question 7

Insulators

Answer 7

Substances which do not allow electric current to flow through them

Question 8

Closed circuit

Answer 8

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

Question 9

Energy is provided

Answer 9

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

Question 10

The battery pumps electrons

Answer 10

From its negative end around a circuit

Question 11

The electrons are attracted

Answer 11

Back to the positive end of the battery

Question 12

Potential difference

Answer 12

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

Question 13

Whenever there is a potential difference

Answer 13

Electricity will flow

Question 14

This potential difference is known as

Answer 14

Voltage and is measured in volts

Question 15

Resistance

Answer 15

Is the opposition to the flow of electrons. The unit is the Ohm, and it is measured using and Ohmmeter

Question 16

If a resistor is placed in an electric circuit

Answer 16

It will slow down the flow of electrons

Question 17

DC

Answer 17

Direct current goes in one direction only

Question 18

AC

Answer 18

Alternating current changes very quickly, many times a second

Question 19

Mains supply

Answer 19

is AC, it flows at a potential difference of 230 Volts

Question 20

The ring circuit

Answer 20

Made of live, neutral and earth wires

Sockets are tapped off at points along the ring circuit

Question 21

Fuse

Answer 21

Is a safety device that prevents the circuit from overheating, it will melt when it is too hot, breaking the circuit

Question 22

Circuit breaker

Answer 22

Is used in the fuse board of the home, and this trips, to stop the flow of current from entering the house

Question 23

Live wire

Answer 23

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

Question 24

Neutral wire

Answer 24

Is blue and is connected to the left hand side

Question 25

Earth wire

Answer 25

Is a safety wire, no electricity flows in the earth wire unless the appliance it is attached to becomes "live" e.g a 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 26

The watt

Answer 26

The unit of electrical power

Question 27

The ESB charges a fee for the number of

Answer 27

Kilowatts (1000 watts) used per hour

Question 28

ESB's unit of electricity is the

Answer 28

kilowatt hour (kWh)

Question 29

A kilowatt hour is the

Answer 29

Electrical energy used by a 1kW applicants running for 1 hour

Question 30

Heating effect

Answer 30

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

Question 31

Chemical effect:

Answer 31

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

Question 32

Magnetic effect:

Answer 32

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

Question 33

Electronics

Answer 33

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

Question 34

Diode

Answer 34

A component that will allow current to flow in one direction only

Question 35

Forward biased

Answer 35

If the positive end of a battery is connected to the positive end of a diode the diode is said to be forward biased and current can flow

Question 36

Reverse biased

Answer 36

If the positive end of the battery is connected to the negative end of the diode it is said to be reverse biased and no electricity can flow

Question 37

A diode can be used to

Answer 37

Change alternating current into direct current

Question 38

Electronic devices sub as radios, tape recorders and calculators

Answer 38

Need low voltage direct current

Question 39

Light emitting diode

Answer 39

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

Question 40

Current will only flow when LED is

Answer 40

Forward biased

Question 41

LEDs use only tiny currents so

Answer 41

A resistor must be connected in series with it

Question 42

LEDs are useful as they are

Answer 42

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

Question 43

A light dependent resistor

Answer 43

Is a resistor whose resistance depends on light

Question 44

When light falls on an LDR

Answer 44

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