Question

The device used for measuring potential difference is known as

• A. Galvanometer
• B. Ammeter
• C. Potentiometer
• D. Voltmeter

Answer 1

The correct option is D

Voltmeter

Explanation for correct option:

In case of option D.

Voltmeter:

1. A voltmeter, is an instrument used for measuring the potential difference, or voltage, between two points in an electrical or electronic circuit.
2. It is connected with the circuit always in parallel to measure voltage.
3. Some voltmeters are intended for use in direct current (DC) circuits; others are designed for alternating current (AC) circuits.
4. Thus, The device used for measuring potential differences is known as the Voltmeter.

Hence, the correct option is option D.

Explanation for incorrect options:

In case of option A.

Galvanometer:

1. A galvanometer is an instrument that can detect and measure small amounts of current in an electrical circuit.
2. It can measure small amounts of current even in milli-amperes.
3. The significant difference between an ammeter and a galvanometer is that the ammeter shows only the current magnitude.
4. Whereas, the galvanometer shows both the direction and magnitude of the current.
5. Thus it is an incorrect option.

In case of option B:

Ammeter:

1. An ammeter is a measuring instrument that is used for the measurement of electric current in an electric circuit.
2. An ammeter has a low resistance.
3. The ammeter is connected in series with the load to measure the electric current flowing through it.
4. The unit for measuring current is called an Ampere, also known as an amp.
5. Thus it is an incorrect option.

In case of option C:

Potentiometer:

1. The potentiometer is an instrument used for measuring the unknown voltage by comparing it with the known voltage.
2. It is defined as a three-terminal resistor having either sliding or rotating contact that forms an adjustable voltage divider.
3. In order to use the potentiometer as a rheostat or variable resistor, it should have only two terminals with one end and the wiper.
4. Potentiometers work by varying the position of a sliding contact across a uniform resistance.
5. Thus it is an incorrect option.

Hence, option D is the correct option.