Which of the following physical quantities has the same dimensional...

The expression $\dfrac{B^2}{2\mu_0}$ represents the magnetic energy density, which is the magnetic energy stored per unit volume.

Dimensional formula of energy $= [ML^2T^{-2}]$
Dimensional formula of volume $= [L^3]$

Dimensional formula of energy density $= \dfrac{[ML^2T^{-2}]}{[L^3]} = [ML^{-1}T^{-2}]$

Now, let us check the dimensions of the given options:
(1) Force $= [MLT^{-2}]$
(2) Power $= [ML^2T^{-3}]$
(3) Pressure $= \dfrac{\text{Force}}{\text{Area}} = \dfrac{[MLT^{-2}]}{[L^2]} = [ML^{-1}T^{-2}]$
(4) Energy $= [ML^2T^{-2}]$

Thus, the expression has the same dimensions as pressure.

Answer: Pressure