Electricity Flashcards
1
Q
Fuse
A
- case is earthed which causes a large current
- if current gets to high
- fuse melts
- breaking circuit
- prevents cable overheating/risk of fire
2
Q
Colours of wires
A
Live = brown Neutral = blue Earth = green and yellow
3
Q
Double insulation
A
Has a plastic casing (which stops current flowing - so doesn’t need an earth wire)
4
Q
Hazards
A
- frayed cables (live wire uncovered)
- long cables (trip hazard)
- water (conductor)
- metal objects in plugs (conductor)
- plug isn’t damaged (live wire exposed)
5
Q
Circuit breakers
A
- large current
- breaks the circuit by opening a switch
6
Q
Resistors
A
- electric current in a resistor causes an energy transfer (causes heat)
- hearing effect increases resistance
- decreases resistance
- can be used for toasters
7
Q
Current
A
Rate of flow of charge around the circuit
-current will only flow through a component if there’s a voltage across that component
8
Q
Voltage
A
Potential difference in charge
9
Q
Resistance
A
Anything in the circuit which reduces current
10
Q
Voltmeter
A
Measures voltage
-always in parallel
11
Q
Ammeter
A
Measures current
-always in series
12
Q
Wire resistance
A
Current is directly proportional to voltage (constant temperature)
13
Q
Diode resistance
A
Current only flows in one direction
14
Q
Filament lamp
A
As temperature increases, the resistance increases (curves)
15
Q
LDR
A
- light dependent resistor
- high resistance in dark
