Question

What is the working principle of voltmeter?

Answer 1

Working principle of voltmeter:

1. According to ohm's law the potential difference across a resistance is directly proportional to the current passing through it.
2. Therefore the deflection in the galvanometer is directly proportional to the potential difference applied across the terminal of the galvanometer.
3. A voltmeter is connected parallel to the circuit and measures the voltage.
4. A parallel connection is used in such a way because voltmeter has a very high resistance value.