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}
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