Question

What is the function of a Voltmeter?

Answer 1

Voltmeter works on the principle of Ohm’s law and measures the potential or voltage difference between two points in an electric circuit. It is denoted by a circle in an electric circuit with the letter $V$ inside it.

Complete answer:
A voltmeter is an instrument that measures the difference in the potential or voltage difference between the two points across which it is connected in an electric circuit.
There are two different types of voltmeter to measure the voltage across the device that are digital voltmeter and analog voltmeter. In digital voltmeter the voltage across the device is display numerically that is analog to digital converter and we will get the exact and accurate value while an analogue voltmeter moves its pointer across a scale in proportion to the circuit voltage and we will not get the exact value of the voltage but an approximate value.
Voltmeter works on the principle of ohm’s law. When a device resistance is constant then the voltmeter deflection will depend on the current as it is directly proportional to the current flowing through it.
In an electric circuit it is represented by the letter V inside a circle with two emerging lines which represents the two ppons of measurement.
Diagram:

Note:
An important point before measuring voltage of a device with the help of voltmeter, the voltmeter must be connected parallel to that device. Remember that some of the voltmeters are designed to be used in DC circuits, others are designed for AC circuits.