The pair of physical quantities not having same dimensions is :

We need to find the pair of physical quantities that do NOT have the same dimensions.

Check each option:

(1) Pressure and Young's modulus: Both have dimensions $$[ML^{-1}T^{-2}]$$. Same. ✓

(2) Surface tension and Impulse:

Surface tension = Force/Length = $$[MLT^{-2}]/[L] = [MT^{-2}]$$
Impulse = Force × Time = $$[MLT^{-2}][T] = [MLT^{-1}]$$
These are different. ✗

(3) Torque and Energy: Both have dimensions $$[ML^2T^{-2}]$$. Same. ✓

(4) Angular momentum and Planck's constant: Both have dimensions $$[ML^2T^{-1}]$$. Same. ✓

The correct answer is Option (2): Surface tension and impulse.