Question

Assertion :In a given situation of arrangement of charges, an extra charge is placed outside the Gaussian surface. In the Gauss Theorem $\oint \overrightarrow{E}.d\overrightarrow{s}=\frac{Q_{in}}{{ϵ}_0}$. $Q_{in}$ remains same whereas electric field $\overrightarrow{E}$ at the site of the element is changed. Reason: Electric field $\overrightarrow{E}$ at any point o the Gaussian surface is due to inside charge only.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason are correct

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

$Q_{en}=$ charge enclosed by the Gaussian surface. So when an extra charge is placed outside the Gaussian surface, $Q_{en}$ will remain same. But the electric will change because the net field is the vector sum of field due to each charge. Therefore, assertion is correct but reason is incorrect.