Question

Current is measured by an instrument called

• A. ammeter
• B. voltmeter
• C. galvanometer
• D. Wheatstone bridge

Answer 1

The correct option is A

ammeter

The explanation for the correct option:

Option (A):

1. An Ammeter is a device used to measure direct or alternating electric current in amperes.
2. An Ammeter can measure a wide range of current values because at high values only a small portion of the current is directed through the meter mechanism.
3. The majority is carried by a shunt connected in parallel with the meter.

The explanation for incorrect options:

1. In the case of option B, a Voltmeter, also known as a voltage meter, is a device that measures the potential difference, or voltage, between two points in an electrical or electronic circuit.
2. In the case of option C, a Galvanometer is a device capable of detecting and measuring small amounts of current in an electrical circuit.
3. In the case of option D, the Wheatstone bridge operates on the null deflection principle, which means that their resistance ratios are equal and the current is zero only in the wire-carrying galvanometer, not in the complete circuit.

Hence, Option (A) is correct.