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

Options

A. `(P-Q)//R`
B. `PQ-R`
C. `PQR`
D. `(P+Q)//P`

Answer

A

Explanation

In this question, it is given that P, Q and R are having different dimension, hence they cannot be added or subtracted , so e can say that (a) and (e) are not meaningful . We cannot say about the dimension of product of these quantities , ehnce (b),(c) and (d) may be meaningful.
Note : In this question,we are certain about the quantity which is never meaningful but we should keep in mind that other may or may not be meaningful.