Q. A physical quantity is represented by $X = M^{\alpha}L^{b}T^{- c}.$ If percentage errors in the measurements of $M,L$ and $T$ are $\alpha\%,\beta\%$and $\gamma\%$ respectively, then total, percentage error is

A) $(\alpha a + \beta b - \gamma c)\%$
B) $(\alpha a + \beta b + \gamma c)\%$
C) $(\alpha a - \beta b - \gamma c)\%$
D) 0%
Explanation

$X = M^{a}L^{b}T^{- c}$ $\therefore\ \ \frac{\mathrm{\Delta}X}{X} = \pm \left\lbrack \alpha\frac{\mathrm{\Delta}M}{M} + b\frac{\mathrm{\Delta}L}{L} + c\frac{\mathrm{\Delta}T}{T} \right\rbrack$ $= \pm \lbrack a\alpha + \beta b + \gamma c\rbrack\%$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.