Question

The error in the measurement of the radius of a sphere is 0.2%. What is the percentage error in the measurement of its surface area?
A. `0.2%`
B. `0.4%`
C. `0.6%`
D. `0.8%`

Answer 1

Correct Answer - b
Given : `(Deltar)/(r)=0.2%`
Area of a sphere `=4pir^(2)`
There is no error in `4pi`, as it is a constant.
`therefore (dA)/(A)=2(Deltar)/(r)=2xx0.2%=0.4%`