JEE Main · 2025 · 29 Jan 2025 · Shift 1 · Units & Measurement

The pair of physical quantities not having same dimensions is :

Answer: (B)

Solution

Torque and energy both have dimensions

[M L^{2} T^{- 2}]

— same.

Angular momentum

[m v r] = [M L^{2} T^{- 1}]

matches Planck's constant

[E / ν] = [M L^{2} T^{- 1}]

— same.

Pressure

[F / A] = [M L^{- 1} T^{- 2}]

matches Young's modulus (stress/strain, with strain dimensionless)

[M L^{- 1} T^{- 2}]

— same.

Surface tension

[F / L] = [M T^{- 2}]

while impulse

[F t] = [M L T^{- 1}]

— these differ.

Surface tension and impulse is the pair without matching dimensions.

JEE Main · 2025 · 29 Jan 2025 · Shift 1 · Single correct option