Electricity

Cards (11)

How does the resistance of a thermistor change with temperature
As temperature increases the resistance decreases
How does the resistance of an LDR change with light?
As light intensity increases, LDR resistance decreases
What can we assume for a series circuit?
The current is the same all the way around, voltage is shared between components
What can we assume for a parallel circuit?
The current is shared between branches, voltage is the same on each branch
How must an ammeter be connected?
In series
How must a voltmeter be connected?
In parallel
Define national grid
System of cables and transformers linking power stations to consumers
State the properties of the UK mains ac supply
230 volts, 50 hertz
Name the 2 types of transformers and what they do
Step up- increases voltage, decreased current
Step down- decreases voltage, increases current
State the colours and functions of the 3 wires in a 3 core cable
Blue= neutral, brown= live, yellow/green= earth
How does an earth wire prevent electrocution?
Allows a large current to flow to earth, then the fuse blows