There is an error of $\pm 0.04 \mathrm{~cm}$ in the measurement of the diameter of a sphere. When the radius…

There is an error of $\pm 0.04 \mathrm{~cm}$ in the measurement of the diameter of a sphere. When the radius is $10 \mathrm{~cm}$, the percentage error in the volume of the sphere is
  1. $\pm 1.2$
  2. $\pm 1.0$
  3. $\pm 0.8$
  4. $\pm 0.6$

Solution

Given, error in diameter $= \pm 0.04$ $\therefore \quad$ Error in radius, $d r= \pm 0.02$ $\therefore$ Per cent error in the volume of sphere $\begin{aligned} & =\frac{d V}{V} \times 100=\frac{d\left(\frac{4}{3} \pi r^3\right)}{\frac{4}{3} \pi r^3} \times 100=\frac{3 d r}{r} \times 100 \\ & =\frac{3 \times( \pm 0.02)}{10} \times 100= \pm 0.6 \end{aligned}$

Asked in: AP EAMCET 2009

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