Question

Potential difference is also called _____________
(A) Voltage
(B) Biot
(C) Coulomb
(D) Ampere

Answer 1

Hint Electric potential difference at any point is described as the change in potential energy per unit charge, similar to field strength which is defined as force per unit charge. The electrical potential can be used to describe an electric field by assigning the scalar quantity $V$ at every point in space.

Complete Step by step solution
In general, $\dfrac{U}{q}$ is the value of the electric potential at a point such that potential is the amount of work done in moving a unit positive charge from infinity to a given location in space.
Suppose a test charge \[q\] is moved in an electric field from point $A$ to point $B$, while the other charges remain fixed. If the electric potential energy changes by ${U_B} - {U_A}$, we define the potential difference between the points $A$ and $B$as ${V_B} - {V_A} = \dfrac{{{U_B} - {U_A}}}{q}$. This is the formula for the potential difference between points based on the electrical potential energy of the two points and the displaced charge \[q\].
Thus potential difference is $\Delta V = \dfrac{{{U_B} - {U_A}}}{q}$; i.e. the change in potential energy per unit charge has the units $\dfrac{{Joule}}{{Coulomb}}$. This is also represented using Voltage.
The unit of potential difference is Voltage and sometimes the terms potential difference and voltage are used interchangeably.

Thus, option (A) is correct.

Additional information The formula for electric potential for a unit charge is $V = \dfrac{1}{{4\pi { \in _ \circ }}}\dfrac{q}{r}$, where $\dfrac{1}{{4\pi { \in _ \circ }}} = 8.988 \times {10^9}N{m^2}{C^{ - 2}}$, \[r\] is the distance of the point whose potential is to be calculated from the charge \[q\]. A potential difference is a difference between this value for different points. The electric potential is a scalar quantity that can be used to define an electric field at any point under consideration except the points where the charge itself is located. Potential difference is therefore the difference in the potentials between two points in space.

Note The other options refer to different units of physical quantities. Biot here may refer to the Biot-Savart’s Law which calculates the magnetic field at a point due to a current-carrying conductor. Coulomb is the unit of charge and Ampere is the unit of current. These options are thus rejected since they are not related to the electric potential difference of a static charge.