Chapter Name: Electric Current
Activity Name: Resistance in Electric Current
In this experiment, students will measure the resistances of different bulbs using a multi-meter. They will then connect these bulbs in series in a circuit powered by a battery.
The potential differences across each bulb and the battery will be measured using voltmeters. The purpose of this experiment is to observe and compare the potential differences across the individual bulbs with the total potential difference across the combination of resistors.
- Different bulbs (at least 3)
- Connecting wires
- Voltmeters (at least 4)
Step by Step Procedure:
- Measure the resistances of each bulb using a multi-meter and record them as R1, R2, and R3 in your notebook.
- Connect the bulbs in series as shown in figure 16, using connecting wires to form a circuit.
- Connect a voltmeter across the terminals of the battery to measure the potential difference (voltage) and record it as V in your notebook.
- Connect voltmeters across the ends of each bulb to measure the potential differences and record them as V1, V2, and V3 in your notebook.
- Compare the potential difference of the battery (V) with the sum of potential differences across the bulbs (V1 + V2 + V3).
- Resistances of different bulbs (R1, R2, R3).
- Potential difference across the battery (V).
- Potential differences across each bulb (V1, V2, V3).
- Ensure the circuit connections are secure and proper to avoid any loose connections.
- Take readings carefully and double-check for accuracy.
- Use appropriate voltage settings on the voltmeters to avoid damage.
- Handle the bulbs and equipment with care to prevent any breakage.
Lesson Learnt from Experiment:
The experiment demonstrates that in a series circuit, the sum of potential differences across individual resistors (bulbs) is equal to the potential difference across the combination of resistors (battery). This observation confirms the conservation of energy in a series circuit.