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

Question

If P , Q and R are physical quantities, having different dimensions, which of the following combinations can never be a meaningful quantity? (A) (PQ - Q2/R) (B) PQ-R (C) (PQ/R) (D) ((PR - Q2)/R)

Tardigrade Admin · Accepted Answer

((P - Q) Q/R) Since P and Q have different dimensions, therefore, their subtraction is not possible

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

$\frac{PQ - Q ^{2}}{R}$

$PQ - R$

$\frac{PQ}{R}$

$\frac{( PR - Q ^{2} )}{R}$

$\frac{( P - Q ) Q}{R}$
Since $P$ and $Q$ have different dimensions, therefore, their subtraction is not possible

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

RPQ−Q2​

PQ−R

RPQ​

R(PR−Q2)​