devarshi-dt-logo

Question:

The dimensions of specific resistance are:

[ML⁻²A⁻¹]

[ML³T⁻³A⁻²]

[ML²T⁻²A⁻²]

[ML³T⁻²A⁻¹]

Solution:

The correct option is B [ML³T⁻³A⁻²]
Resistance of a substance=R=ρl/A ⇒ρ=RA/l=V/IA
Dimension of V is [ML²T⁻³A⁻¹]
Dimension of I is [A]
Dimension of A is [L²]
Dimenstion of l is [L]
Thus dimension of ρ is [ML³T⁻³A⁻²]