Q.

A solid non-conducting sphere of radius R having variable volume charge density d=ArR where r is the distance from centre. If electric field at distance R2 from the centre of charged sphere is E=2Rε0 N/C. Value of A16 will be

1 2  
2 4  
3 6  
4 8  

Ans.

(1)

According to Gauss law

∮E→·ds→=qinε0

qin=∫0R/2d·4πr2 dr

Solving A16=2