Q 11-01-211JEE MainJEE Main 2020 (5 Sep, Shift 1)Easy
A physical quantity $z$ depends on four observables $a$, $b$, $c$ and $d$, as $z = \dfrac{a^{2}b^{2/3}}{\sqrt{c}\,d^{3}}$. The percentage of error in the measurement of $a$, $b$, $c$ and $d$ are $2\%$, $1.5\%$, $4\%$ and $2.5\%$ respectively. The percentage of error in $z$ is:
Answer: (D) $14.5\%$
$$\frac{\Delta z}{z} = 2\frac{\Delta a}{a} + \frac23\frac{\Delta b}{b} + \frac12\frac{\Delta c}{c} + 3\frac{\Delta d}{d} = 4 + 1 + 2 + 7.5 = 14.5\%$$
Solution by Sreeraj P, M.Sc Physics