Q 11-01-234JEE MainJEE Main 2017 (9 Apr)Easy
A physical quantity $P$ is described by the relation $P = a^{\frac12}b^2c^3d^{-4}$. If the relative errors in the measurement of $a$, $b$, $c$ and $d$ respectively, are $2\%$, $1\%$, $3\%$ and $5\%$, then the relative error in $P$ will be:
Answer: (D) $32\%$
For a product of powers, the maximum relative error is the sum of (|power| × relative error):
$$\frac{\Delta P}{P} = \frac12(2\%) + 2(1\%) + 3(3\%) + 4(5\%) = 1 + 2 + 9 + 20 = 32\%$$
Solution by Sreeraj P, M.Sc Physics