Dimensions of $CR$ are those of

$Assertion$ : The dimensional formula for relative velocity is same as that of the change in velocity.
$Reason$ : Relative velocity of $P$  w.r.t. $Q$ is the ratio of velocity of $P$ and that of $Q$.

The dimension of magnetic field in $M, L, T$ and $C$ (coulomb) is given as 

${\mu _0}$ and ${\varepsilon _0}$ denote the permeability and permittivity of free space, the dimensions of ${\mu _0}{\varepsilon _0}$ are

The dimensions of ${e^2}/4\pi {\varepsilon _0}hc$, where $e,\,{\varepsilon _0},\,h$ and $c$ are electronic charge, electric permittivity, Planck’s constant and velocity of light in vacuum respectively

Dimensional formula for torque is