$(a)\;\alpha\;l^4\qquad(b)\;2\;\alpha\;l^4\qquad(c)\;3\;\alpha\;l^4\qquad(d)\;4\;\alpha\;l^4$

Want to ask us a question? Click here

Browse Questions

Ad |

0 votes

0 votes

Answer : (c) $\;3\;\alpha\;l^4$

Explanation :

Electric field is along +ve x- axis . Therefore field lines are perpendicular to faces ABFE and CDHG . At all other faces field lines are tangential . So net flux passing these four faces will be zero .

Flux entering face $\;ABFE|_{x=l}=(\alpha\;l^2)\;l^2$

$=\alpha\;l^4$

Flux entering face $\;CDHG|_{x=2l}=(\alpha\;4\;l^2)\;l^2$

$=4\;\alpha\;l^4$

net flux passing through cube

$=4\;\alpha\;l^4-\alpha\;l^4$

$=3\;\alpha\;l^4\;.$

Ask Question

Tag:MathPhyChemBioOther

Take Test

x

JEE MAIN, CBSE, NEET Mobile and Tablet App

The ultimate mobile app to help you crack your examinations

...