Question

Which of the following is the dimension of electrostatic potential?
1. [ML²T^-2 C]
2. [ML²T^-3I^-1]
3. [ML²T^-1]
4. [M²L^-2T^-3]

Answer 1

Correct Answer - Option 2 : [ML²T^-3I^-1]

CONCEPT: 

• The amount of work done in moving a unit positive charge in an electric field from infinity to that point without accelerating the charge against the direction of the electric field is electrostatic potential.
• The electrostatic potential is given by

\(⇒ V = \frac{W}{q}\)

Where V = Electrostatic potential , W = Work , q = Charge

• Dimensions are the power to fundamental quantities is to be raised to represent the quantity

EXPLANATION : 

• The dimension of electrostatic potential can be found out as 

\(⇒ V = \frac{W}{q}\)       ----(1)

• Dimension of work is

⇒ W = [ ML2T-2]

• The dimension q can be found out as

\(\Rightarrow I = \frac{q}{t}\)

\(⇒ q = I\times t\)

Substituting the proper dimensions

\(⇒ q = [I]\times [T] = [IT]\)

Substituting the dimension of q and W in equation 1

\(⇒ V = \frac{[ML^{2}T^{-2}]}{[IT]} = [ML^{2}I^{-1}T^{-3}]\)

• The dimension of V is [ML2T-3I-1]