RW BTEC PRINCIPLES
Name ………………………………………………………………………………………………………
Calculating resistance
Build a circuit that contains a switch, a small variable resistor and a
bulb.
Draw your circuit below:
Take readings from your ammeter and voltmeter and write them
down. Calculate the resistance using Ohm’s Law.
(Resistance = Voltage ÷ Current)
Change the amount of resistance in the circuit and write down the
values of voltage and current. Calculate the resistance. Repeat this
once more.
Measured Voltage
Units are………
Measured Current
Units are……….
Calculated
Resistance
Units are…………..
RW BTEC PRINCIPLES
Name ………………………………………………………………………………………………………
Predicting the current or voltage if given the other two.
Use Ohm’s Law to calculate the missing value.
Remember:
Voltage = Current × Resistance
Resistance = Voltage ÷ Current
Current = Voltage ÷ Resistance
Current
(Units………..)
Voltage
(Units………)
5
100
60
12
3
3
10
15
5000
800
Resistance
(Units………..)
20
50