question_answer

Out of the following pairs, which one does not have identical dimensions?         [AIEEE 2005]

A) Angular momentum and Planck's constant

B) Impulse and momentum

C) Moment of inertia and moment of a force

D) Work and torque

Correct Answer: C

Solution :

[c] As, Planck's constant has unit J-s and angular momentum also has the unit J-s. So these two have identical dimension.

Similarly impulse is change of momentum. So, impulse and momentum have same dimension product of force and distance. So, these two have same dimension.

As             \[l=m{{r}^{2}}\]

\[[l]\,=[M{{L}^{2}}]\]

and moment of force