If P, Q, R are physical quantities, having different dimensions, which of the following combinations can never be a meaningful quantity?

A

R(P−Q)​

B

PQ−R

C

RPQ​

D

R(P−Q2)​

Medium

Correct option is A)

Physical quantities having different dimensions cannot be added or subtracted.
As P, Q and R are physical quantities having different dimensions, therefore they can neither be added nor be subtracted. Thus, (a) can never be a meaningful quantity.