Question

The $SI$ unit of universal gravitational constant is:

• A. $N{m}^{2}k{g}^{-2}$
• B. $N{m}^{-2}k{g}^2$
• C. $N{m}^{2}k{g}^2$
• D. $N{m}^{-2}k{g}^{-2}$

Answer 1

The correct option is A $N{m}^{2}k{g}^{-2}$

As per universal law of gravitation,
$F=\frac{GMm}{d^2}$
$G=\frac{F{d}^2}{Mm}$
where:
$F:$ Gravitational force, whose $SI$ unit is Newton $\left(N\right)$
$d:$ Distance between the masses, whose $SI$ unit is metre $\left(m\right)$
$M,m:$ Masses whose $SI$ unit is $kg$.

Therefore, the $SI$ unit of $G$ is: $N{m}^{2}k{g}^{-2}$.