Question

Charges ${\theta }_1$ and ${\theta }_2$ lie inside and out side respectively for a closed surface s. Let E be the field at a point on S and $\varphi$ be flux of E over S

• A. If only ${\theta }_1$ changes, both E & $\varphi$ charges
• B. If only ${\theta }_2$ changes, E will change but $\varphi$ will not change
• C. If ${\theta }_1=0,{\theta }_2\ne 0$ then $E\ne 0$ but $\varphi =0$
• D. If ${\theta }_1=0,{\theta }_2\ne 0$ then $E=0$ but $\varphi \ne 0$

Answer 1

The correct option is C If ${\theta }_1=0,{\theta }_2\ne 0$ then $E\ne 0$ but $\varphi =0$

Charges ${\theta }_1$ and ${\theta }_2$ lie inside and out side respectively.

For a closed surface $=S$

Let $E=$ the field at a point on $S$ and $\phi$ be flux of $E$ over $S$.

In this context if only ${\theta }_1$ changes, both $E$ and $\phi$ charges and if any ${\theta }_2=$ changes, $E$ will change but $\phi$ will not change.

If ${\theta }_1=0$ and ${\theta }_2\ne 0$

$E\ne 0$ but $\phi =0$

This point is to be noted.