Static and Current Electricity Flashcards Preview

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Flashcards in Static and Current Electricity Deck (45)
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1
Q

Polythene rod gains electrons

A

If a woollen cloth is rubbed on it (becomes negatively charged

2
Q

A perspex rod loses electrons

A

If it is rubbed by a woollen cloth (becomes positvely charged)

3
Q

Earthing

A

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

4
Q

Electric current

A

The flow of electric charge

5
Q

Conductors

A

Substances which allow electric current flow through them freely

6
Q

Insulators

A

Substances which do not allow electric current to flow through

7
Q

Closed curcuit

A

Needed for the current to flow if there is a break in the current then the current won’t flow

8
Q

Energy provided

A

A battery or power pack it is needed to move the current around the circuit

9
Q

The battery pumps electrons

A

From its negative end around the circuit

10
Q

The electrons are attracted

A

To the positive end of the battery

11
Q

Potential difference

A

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

12
Q

Whenever there is potential difference

A

Electricity will flow

13
Q

This potential difference is known as voltage

A

And is measured in volts

14
Q

Resistence

A

The opposition to the flow of electrons the unit is the Ohm and it is measured using a ohmeter

15
Q

is placed in an eletric circuit it will slow down the flow of electrons

A

If a Resistor

16
Q

Static electricity

A

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

17
Q

Ohms law

A

Staes the voltage is directly proportional to current

18
Q

Direct current/dc

A

It goes in one direction only e.g the current from a battery

19
Q

Alternating current/AC

A

Changes very quickly many times a second

20
Q

Mains supply

A

The electricity in our homes supplied by the ESB is A.C

21
Q

Ring circuit

A

All households have a ring circuit made of live nuetral and earth wire
Sockets are tapped off at points along this ring circuit

22
Q

Fuse

A

A safety device that prevents the ciruit from overheating it will melt when it is too hot breaking the circuit

23
Q

Ciruit breaker

A

Limits the size of the current flowing in the current, a safety feature to prevent overheating but is based on magnetic effect of electricity

24
Q

Live wire

A

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

25
Q

The neutral wire

A

Its blue and is connected to the left hand side

26
Q

The earthwire

A

Is a safety wire no electricity flows in the earth wire unless the appliance it is attached to becomes “live” e.g toaster in this case the earth wire would carry the current to the earth instead of you electrocuting yourself should you touch the toaster

27
Q

Watt

A

The unit of electrical power

28
Q

The ESB charges a fee for the number of

A

Kilowatts (1000 watts) used per hour

29
Q

ESB units of electricity

A

The kilowatt hour(kWh)

30
Q

Kilowatt hour

A

The electrical energy used by a 1kW appliance running for an hour

31
Q

Heating effect

A

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

32
Q

Chemical effect

A

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

33
Q

Magnetic effect

A

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

34
Q

Electronics

A

The careful and exact control of tiny amounts of electric current

35
Q

Diode

A

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

36
Q

Forward biased

A

The positive end of a battery is connected to the positive end of a diode

37
Q

Reverse bias

A

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

38
Q

Diodes are used to …

A

Change alternating current into direct current

39
Q

Electronic devices such as radios, tape recorders and calculators

A

Need low voltage direct current

40
Q

Light emitting diode

A

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

41
Q

Current will only flow when LED is

A

Forward biased

42
Q

LED’s use only tiny currents

A

So a resistor must be connected in series with it

43
Q

LED’s are useful because they are

A

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

44
Q

LDR

A

Light dependent resistor whose reistance depends on light

45
Q

When lights fall on an LDR

A

Its resistance decreases, this low resistance will allow a current throught the circuit