Hello,

 

Today morning while solving problems frm my correspondence course I came across some questions where i got confused.

Everyone is requested to drop their views regarding the following ques..

They r

1.A point charge is placed at the centre of a spherical Gaussian surface.Is flux   is changed (a) if the surface is replaced by a cube of the same volume?

 (b) If the sphere is replaced by a cube of 1/10 the volume?

 

2.A point charge q is placed at one corner of a cube of edge a. What is the flux through each of the cube faces?

 

 

(a) See flux is given by the mathematical relation q_enc/ where q_enc is the total charge enclosed by your gaussian surface that is inside it.So it is independent of the volume of the surface and also of any charge outside it.

 

(b)this is a good question.Consider a larger cube of side 2a where q is at the centre(just like placing cubes on the side and top of the existing cube).Now from symmetry of the figure,through each face,flux is same,so total no. of faces is 6*4=24.so ans is q/24