If the radius of a sphere is measured to be `( 2.1 +- 0.05)`cm.Calculate the surface area ( in `cm^(2)`)

Options

A. `54.45 pm 2.46`
B. `55.44 pm 2.64`
C. `52.03 pm 4.26`
D. `45.54 pm 2.68`

Answer

C

Explanation

`S = 4pi r^(2) = 4 xx (22)/(7) xx (2.1) ^(2)`
`= 55. 44 cm ^(2)`
`(Delta S )/(S) =2 (( Delta r )/(r))`
`Delta S = 2 (( Delta r )/(r)) S`
`= (2 xx 0.05 xx 55.44)/(2.1) = 2. 64`
`therefore Delta S = ( 55.44 pm 2. 64) cm ^(2)`