Q. If $u_{1}$ and $u_{2}$ are the units selected in two systems of measurement and $n_{1}$ and$\ n_{2}$ their numerical values, then
A) $n_{1}u_{1} = n_{2}u_{2}$
B) $n_{1}u_{1} + \ n_{2}u_{2} = 0$
C) $n_{1}n_{2} = u_{1}u_{2}$
D) $\left( n_{1} + u_{1} \right) = (n_{2} + u_{2})$
Explanation
Physical quantity$\ (p) =$ Numerical value $(n) \times Unit\ (u)$ If physical quantity remains constant then $n \propto 1/u$ $\therefore n_{1}u_{1} = n_{2}u_{2}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.