If $\mathrm{G}$ be the gravitational constant and $\mathrm{u}$ be the energy density then which of the following quantity have the dimension as that the $\sqrt{\mathrm{uG}}$ :

If the capacitance of a nanocapacitor is measured in terms of a unit $u$ made by combining the electric charge $e,$ Bohr radius $a_0,$ Planck's constant $h$ and speed of light $c$ then

Which two of the following five physical paramenters have the same dimensions $?$ 

$(1) $ energy density

$(2)$ refractive index

$(3) $ dielectric constant

$(4) $ Young's modulus

$(5)$ magnetic field

$ML{T^{ - 1}}$ represents the dimensional formula of

The pair having the same dimensions is

The dimensional formula for Planck's constant $(h)$ is