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).
A temperature difference can generate e.m.f. in some materials. Let $ S $ be the e.m.f. produced per unit temperature difference between the ends of a wire, $ \sigma $ the electrical conductivity and $ \kappa $ the thermal conductivity of the material of the wire. Taking $ M, L, T, I $ and $ K $ as dimensions of mass, length, time, current and temperature, respectively, the dimensional formula of the quantity $ Z = \frac{S^2 \sigma}{\kappa} $ is:
A quantity \( X \) is given by: \[ X = \frac{\epsilon_0 L \Delta V}{\Delta t} \] where:
- \( \epsilon_0 \) is the permittivity of free space,
- \( L \) is the length,
- \( \Delta V \) is the potential difference,
- \( \Delta t \) is the time interval.
The dimension of \( X \) is the same as that of: