Dimensional formula of Planck constant is:

The correct answer is Option (4) → \( [ML^{2}T^{-1}] \)

Planck's constant links the energy of a photon to its frequency, \( E = h\nu \), so its dimensions are those of energy divided by frequency.

    \( \displaystyle h = \frac{E}{\nu} \)

    \( [E] = [ML^{2}T^{-2}] \)
    \( [\nu] = [T^{-1}] \)

    \( \displaystyle [h] = \frac{[ML^{2}T^{-2}]}{[T^{-1}]} = [ML^{2}T^{-1}] \)

These are also the dimensions of angular momentum, as in Bohr's condition \( mvr = nh/2\pi \).

NCERT (2026-27):
Summary – …