Static and current Electiricity

Question 1

Polythene rod

Answer 1

Gains electrons

Question 2

A 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

Is 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

Are substances which allow electric current to flow through them freely

Question 7

Insulators

Answer 7

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

Question 8

Closed circuit

Answer 8

Is needed for the current to flow, if there is a break in a circuit then the current won’t flow => the electrical energy can’t get through

Question 9

Energy 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/paper pack

Question 13

Whenever there is a potential difference

Answer 13

Electricity will flow

Question 14

This potential difference is known as voltage

Answer 14

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 an ohmmeter

Question 16

If a resister

Answer 16

Is placed an electric circuit, it will slow down the flow of electrons

Question 17

Ohms law

Answer 17

Ohms law states that voltage is directly proportional to current.

Question 18

DC

Answer 18

Direct current goes in one direction only

Question 19

AC

Answer 19

Alternate current charges very quickly many times a second

Question 20

Mains supply

Answer 20

Is A.C it flows at a potential difference of 230 Volts

Question 21

DC

Answer 21

Direct current goes in one direction only

Question 22

AC

Answer 22

Alternate current charges very quickly many times a second

Question 23

The ring circuit

Answer 23

Made of live, neutral and earth wires. Sockets are tapped off at points along this ring circuit

Question 24

Fuse

Answer 24

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

Question 25

Circuit breaker

Answer 25

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

Question 26

Live wire

Answer 26

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

Question 27

Neutral wire

Answer 27

Is blue and is connected to the left hand side

Question 28

Earth wire

Answer 28

Is a safety wire, no electricity flows in the earth wire unless the appliance it is attached to becomes "live" e.g. A toaster, I'm this case the earth wire would carry the current to the earth intend if you electrocuting yourself should you though the toaster

Question 29

Watt

Answer 29

Is the unit of electrical power

Question 30

ESB charges a fee for the numbers of

Answer 30

Kilowatts(1000 watts) used per hour

Question 31

ESB's unit of electricity

Answer 31

Is the kilowatt hour (kWh)

Question 32

Kilowatt hour

Answer 32

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

Question 33

Heating effect

Answer 33

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

Question 34

Chemical effect

Answer 34

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

Question 35

Magnetic effect

Answer 35

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

Question 36

Electronics

Answer 36

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

Question 37

Diode

Answer 37

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

Question 38

Forward biased

Answer 38

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

Question 39

Reverse biased

Answer 39

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 40

A diode can be used

Answer 40

To change alternating current into direct current

Question 41

Electronic devices such as radios, tape recorders and calculators

Answer 41

Need low voltage direct current

Question 42

Light emitting diode

Answer 42

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

Question 43

Current will only flow when LED

Answer 43

Is forward biased

Question 44

LED's use only tiny currents

Answer 44

So a resistor must be connected in series with it

Question 45

LED's are useful as they are

Answer 45

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

Question 46

A light dependent resistor

Answer 46

Is a resistor whose resistance depends on light

Question 47

When light falls on an LDR

Answer 47

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