12th Class
Physics
Electric Charges and Fields
Question Bank
MCQ - Electric Charges and Fields
question_answer
A cylinder of radius R and length L is placed in a uniform electric field E parallel to the cylinder axis. The total flux for the surface of the cylinder is given by:
A)\[2\pi {{R}^{2}}E\]
B)\[\frac{{{R}^{2}}}{E}\]
C)\[\frac{\pi {{R}^{2}}}{E}\]
D)zero
Correct Answer:
D
Solution :
(d) zero Flux through surface A, \[{{\phi }_{A}}=E\times \pi {{R}^{2}}\] Flux through surface B, \[{{\phi }_{B}}=-E\times \pi {{R}^{2}}\] Flux through curved surface, \[C=\int{E\,.\,ds}\] \[\int{E\,ds\,\cos \,90{}^\circ =0}\] \[\therefore \] Total flux through cylinder \[={{\phi }_{A}}+{{\phi }_{B}}+{{\phi }_{C}}=0\]