question_answer 20)

A point charge causes an electric flux of to pass through a spherical Gaussian surface of 10.0 cm radius centred on the charge.                 (a) If the radius of the Gaussian surface were doubled, how much flux would pass through the surface?                 (b) What is the value of the point charge?  

Answer:

(a) The electric flux through new Gaussian surface remains same i.e., because the charge enclosed remains same in this case also.                 (b) Using we get                                 i.e.,