A) \[E\pi {{r}^{2}}\,sin \theta \]
B) \[\frac{E}{3}\pi r/\,sin \theta \]
C) \[E\pi {{r}^{2}}\]
D) \[\frac{E}{3}\pi {{r}^{2}}/\,cos \theta \]
Correct Answer: C
Solution :
Construct a plane surface on the base of cone as shown in figure as charge enclosed by this closed surface is zero, so flux crossing this surface is equal to zero. i.e., \[\phi =0\] \[\Rightarrow \,\,\,{{\phi }_{plane\,\,surface}}+\,\,{{\phi }_{plane\,\,surface}}\,\,=\,\,0\] \[{{\phi }_{curved\,\,surface}}~=\,\,-{{\phi }_{plane\,\,surface}}\] \[=\,\,-\left( E.A \right)\] \[=\,\,-EA cos 180{}^\circ \] \[=\,\,+E\pi \,{{r}^{2}}\,\,=\,\,E\pi \,{{r}^{2}}\]You need to login to perform this action.
You will be redirected in
3 sec