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

Question

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

Tardigrade Admin · Accepted Answer

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.

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

$\frac{( P - Q )}{R}$

$PQ - R$

$\frac{PQ}{R}$

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

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.

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

R(P−Q)​

PQ−R

RPQ​

R(PR−Q2)​

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.

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

$\frac{( P - Q )}{R}$

$PQ - R$

$\frac{PQ}{R}$

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

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.