Consider a unigorm annular sphere of density p and internal radius 2m an external radius 4m. The graviational field strength at a point at a distance r=3 m, from the centre of shaper is :

Options

A. `-(32Gpip)/(9)`
B. `-4Gpi`
C. `-(32Gpip)/(9)`
D. `(76)/(27)Gpip`

Answer

D

Explanation

`E=(GM)/(r^(2))`
`EG=(GM)/(9)`
Where M `rArrpx[(4pi)/(3)[3^(3)-2^(3)]]`
`rArr(pxx4pixx19)/(3)`
`rArr(Gpip76)/(27)`