Q 11-01-028NEETEAMCET 2010 (Medical)Medium
A body weighs $22.42\ \text{g}$ and has a measured volume of $4.7\ \text{cc}$. The possible errors in the measurement of mass and volume are $0.01\ \text{g}$ and $0.1\ \text{cc}$. The maximum percentage error in the density will be
Answer: (B) $2.2\%$
$\rho = \dfrac{M}{V}$, so percentage errors add:
$$\frac{\Delta\rho}{\rho}\times 100 = \frac{0.01}{22.42}\times 100 + \frac{0.1}{4.7}\times 100 \approx 0.045\% + 2.13\% \approx 2.2\%$$
Almost all of the error comes from the volume, which was measured much less precisely.
Solution by Sreeraj P, M.Sc Physics