Question

What is the zero error of voltmeter and ammeter?

Answer 1

Voltmeter:

1. It is an instrument used for measuring the electric potential difference between two points in an electric circuit. It is connected in parallel.
2. The internal resistance of a voltmeter is high. The major reason for doing this is to measure the potential difference between the two points in a circuit.
3. As a result, the current in the device stays constant. In other words, the voltmeter's high resistance will make it difficult for the current to pass through it. This enables the instrument to measure voltage accurately.

An illustrative diagram of the voltmeter is shown below.

Ammeter:

1. It is used to measure the current in a circuit.
2. It is usually connected in series with the circuit.
3. The resistance of an ammeter is low. To measure the electric current flowing through a load, an ammeter is connected in series with the load. Since the ammeter has a very low resistance, it has no effect on the current when it is connected in series with any circuit.

An illustrative diagram of the ammeter is shown below.

Zero error:

1. When a circuit is not connected, the ammeter or voltmeter's pointer is exactly at zero, and the instrument is said to have no zero error.
2. The zero error is negative if the pointer is above the zero mark.
3. Subtract the number of divisions if it is above the zero point from the reading.
4. The final reading is equal to the reading on the instrument when connected in the circuit minus zero error.