Of the following, the pair of physical quantities not having the same dimensional formula is:
Show Hint
For dimensional analysis, express the physical quantity in terms of fundamental units:
\[
M \rightarrow \text{Mass}, L \rightarrow \text{Length}, T \rightarrow \text{Time}
\]
Matching dimensions verifies equivalent physical quantities.
Step 1: Dimensional Analysis
1. Work and Torque
- Work: \( [ML^2T^{-2}] \)
- Torque: \( [ML^2T^{-2}] \)
- Same dimensional formula.
2. Angular Momentum and Planck’s Constant
- Angular Momentum: \( [ML^2T^{-1}] \)
- Planck’s Constant: \( [ML^2T^{-1}] \)
- Same dimensional formula.
3. Stress and Linear Momentum
- Stress: \( [ML^{-1}T^{-2}] \)
- Linear Momentum: \( [MLT^{-1}] \)
- Different dimensional formula.
4. Surface Tension and Force Constant
- Surface Tension: \( [MT^{-2}] \)
- Force Constant: \( [MT^{-2}] \)
- Same dimensional formula.
Conclusion:
Stress and linear momentum do not share the same dimensional formula. Thus, the correct answer is:
\[
\text{Stress and linear momentum}
\]