Q.

Five charges q1,q2,q3,q4 and q5 are fixed at their positions as shown in figure. S is a Gaussian surface. The Gauss's law is given by ∮E→·ds→=qε0. Which of the following statements is correct

1 E on the LHS of the above equation will have a contribution from q1, q5 and q3, while q on the RHS will have a contribution from q2 and q4 only  
2 E on the LHS of the above equation will have a contribution from all charges while q on the RHS will have a contribution from q2 and q4 only  
3 E on the LHS of the above equation will have a contribution from all charges while q on the RHS will have a contribution from q1, q3 and q5 only  
4 Both E on the LHS and q on the RHS will have contributions from q2 and q4 only.  

Ans.

(2)

According to Gauss's theorem in electrostatics, ∮E→·ds→=qε0. Here, E is due to all the charges q1,q2,q3,q4 and q5. As q is charge enclosed by the Gaussian surface, therefore, q=q2+q4