### ZIMSEC O Level Combined Science Notes: Experiment: Finding the resistance of a resistor using a voltmeter

**Aim: ** To find the resistance of a resistor in a circuit using voltmeter

**Materials: **cells, ammeter, resistor,switch, leads with crocodile clips

**Method**

- Set up the circuit as shown above
- Close the switch
- Read and record values of the ammeter and voltmeter measurements
- Repeat steps 2 and 3 with two, then three then four cells respectively
- Use Ohm’s Law to find the resistance of the resistor
- Use Ohm’s law to find resistance

**Results and Observations**

- Current increases proportionally with an increase in voltage

**Example**

- For example if the current is 2 Amps and the 6 Volts
- Then the resistance is 3 Ohms
- This is found by the formula
- R=\dfrac{V}{I}

To access more topics go to the Combined Science Notes page.