A quantity X is given by ε₀L( ΔV/Δt) where ε₀ is the the permittivity of the free space, L is a length, ΔV is a potential difference and Δt is a time interval. The dimensional formula for X is the same as that of
Correct Answer :
current
Solution :
The correct option is current.
To find the physical quantity that has the same dimensional formula as , let us analyze the given formula:
where is the permittivity of free space, is a length, is a potential difference, and is a time interval.
First, recall the formula for the capacitance of a parallel-plate capacitor:
Here, represents area (dimension of ) and represents distance (dimension of ).
In terms of dimensions, we can write:
This shows that the product has the dimensions of capacitance .
Now, substituting capacitance in place of in our equation for , we get:
Since the charge on a capacitor is given by the relation , the term represents the change in charge .
Substituting this relation into the equation, we obtain:
The quantity represents the rate of flow of charge with time, which is the definition of electric current. Therefore, the dimensional formula of is the same as that of current.
Access expert-curated educational resources and study materials—completely free.
Create, conduct, and manage professional online assessments with Crey. Perfect for teachers and institutes.
Copyright © 2026 Crey. All Rights Reserved.