Question

What is the S.I. unit of electric potential?

• A. Ampere
• B. Volt
• C. Volt-meter
• D. Coulomb

Answer 1

The correct option is B

Volt

The explanation for the correct option:

1. Electric potential is the work required to move a unit charge from one point to other against an electric field.
2. Electric potential depends on the amount of work required to move charge from one point to other against an electric field.
3. The mathematical expression for electric potential is $V=K\frac{q_0}{d}$, where $V=$electric potential, $K$ = coulomb's constant, $q_0$= testing charge, $d$ = distance.
4. Volt is the SI unit of electric potential.
5. The dimension of electric potential is $[{\mathrm{M}}^1{\mathrm{L}}^2{\mathrm{T}}^{-3}{\mathrm{I}}^{-1}]$.
6. It is a vector quantity.

Hence, option (B) is correct.

An illustrative diagram of electric potential is given below.

The explanation for the incorrect options:

1. Option A: Ampere is the SI unit of electric current.
2. Option C: Volt-meter is the SI unit of an electric field.
3. Option D: Coulomb is the SI unit of electric charge.

Hence, Options (A), (C), and (D) are incorrect.