Static and Current Electricity

Question 1

Polythene rod

Answer 1

Gains electrons

Question 2

Perspex rods

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

An electric current

Answer 4

Is a flow of Electric charge

Question 5

Conductors

Answer 5

Are substances which allow electric current to flow through them freely

Question 6

Insulators

Answer 6

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

Question 7

Closed circuit

Answer 7

Is needed for current to flow. If there is a break the current won’t flow

Question 8

Energy is provided

Answer 8

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

Question 9

The battery pumps electrons

Answer 9

From its negative end back to the positive end around the circuit

Question 10

The electrons are attracted

Answer 10

Back to the positive end of the battery

Question 11

Potential difference

Answer 11

The difference in elctrical pressure between the positive end of a battery and negative ends of a battery

Question 12

Whenever there is a potential difference

Answer 12

Electricity will flow

Question 13

This potential difference is known as

Answer 13

Voltage and is measured in volts

Question 14

Resistence

Answer 14

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

Question 15

If a resister

Answer 15

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

Question 16

Ohms Law

Answer 16

Ohms law states that vo,take is directly proportional to current.

Question 17

Static electricity

Answer 17

A build of electric charge that can build up on good insulators

Question 18

DC

Answer 18

Direct current goes in one direction only

Question 19

AC

Answer 19

Alternating current changes very quickly, many times a second

Question 20

Mains supply

Answer 20

is A.C

It flows at a potential difference of 230V

Question 21

The ring circuit

Answer 21

Made of live, neutral and earth wires.

Sockets are tapped off at points along the ring circuit

Question 22

Fuse

Answer 22

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

Question 23

Circuit breakers

Answer 23

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

Question 24

Live wire

Answer 24

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

Question 25

Neutral wire

Answer 25

Is blue and is connected to the left hand side

Question 26

Earth wire

Answer 26

Is a safety wire, no electricity flows in the earth wire unless the appliance it is attached to becomes "live" eg toaster, in this case the earth instead of you electrocuting yourself should you touch the toaster

Question 27

The watt

Answer 27

Is the unit of electrical power

Question 28

The ESBcharges a fee for the number of

Answer 28

kilowatts used per hour

Question 29

ESBs unit of electricity is

Answer 29

The kilowatt hour

Question 30

A kilowatt hour is

Answer 30

The electrical energy used by a 1Kw appliance running for one hour

Question 31

Heating effect

Answer 31

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

Question 32

Chemical effect

Answer 32

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

Question 33

Magnetic effect

Answer 33

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

Question 34

Electronics

Answer 34

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

Question 35

Diode

Answer 35

Is a component which allows current to flow n one direction only

Question 36

Forward biased

Answer 36

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

Question 37

Reverse biased

Answer 37

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 38

A diode can be used to

Answer 38

Change alternating current into direct current

Question 39

Electronic devices such as radios, tape recorders and calculators

Answer 39

Need low voltage direct current

Question 40

A light emitting diode

Answer 40

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

Question 41

Current will only flow when LED

Answer 41

is forward biased

Question 42

LEDs use only tiny currents so

Answer 42

A resistor must be connected in series with it

Question 43

LEDs are useful as they are cheap

Answer 43

Reliable and long lasting and use far less current than other light bulbs

Question 44

A light dependent resistor

Answer 44

Is a resistor whose resistance depends on light

Question 45

When light falls on an LDR

Answer 45

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