Define electric flux. When will the flux is said to be positive and negative?

Asked by Topperlearning User | 16th Apr, 2015, 10:52: AM

Expert Answer:

Electric flux over an area in an electric field is defined as the total number of electric field lines crossing this area. It is represented by

                                                     

 

 

 

 

 

where begin mathsize 11px style straight E with rightwards arrow on top end style is electric field intensity over a small area element begin mathsize 11px style straight d straight s with rightwards arrow on top end style, and θ is the angle between begin mathsize 11px style straight E with rightwards arrow on top end style and outward drawn normal to area element begin mathsize 11px style straight n with hat on top end style.

begin mathsize 11px style straight ϕ subscript straight E end style is said to be positive, if flux lines are flowing outwards that is if θ < 900  and

begin mathsize 11px style straight ϕ subscript straight E end style is said to be negative, if flux lines are flowing inwards that is if θ >900.

Answered by  | 16th Apr, 2015, 12:52: PM