The relative error in the determination of the surface area of a sphere is α. Then the relative error in the determination of its volume is :
Given- Relative error in surface area $\alpha$
To find - Relative error in volume
Solution- Surace area $A = 4\pi r^2$
Relative error in radius $\frac{\Delta r}{r} = \frac{1}{2} \cdot \frac{\Delta A}{A} = \frac{\alpha}{2}$.
Volume of sphere $V = \frac{4}{3}\pi r^3$
So, relative errors in volume $\frac{\Delta V}{V} = 3 \cdot \frac{\Delta r}{r} = 3 \cdot \frac{\alpha}{2} = \frac{3\alpha}{2}$