Step 1: Recall the definition of Planck’s constant.
Planck's constant \( h \) appears in the relation \( E = h \nu \), where \( E \) is energy and \( \nu \) is frequency.
Step 2: Use dimensional formulas.
Energy: [ML2T-2]
Frequency: [T-1]
Step 3: Derive the dimensional formula of \( h \).
Since \( h = \frac{E}{\nu} \), we have:
\[ [h] = \frac{[ML^2T^{-2}]}{[T^{-1}]} = [ML^2T^{-1}] \] So the dimensional formula of Planck’s constant is: [ML2T-1]
Step 4: Select the correct option.
The derived dimensional formula [ML2T-1] matches option (3).

Match List-I with List-II.
Choose the correct answer from the options given below :
Find the variance of the following frequency distribution:
| Class Interval | ||||
| 0--4 | 4--8 | 8--12 | 12--16 | |
| Frequency | 1 | 2 | 2 | 1 |