The electric flux through the circle is given by,
Where E is the electric field and dS is the area vector through which E passes. From problem 3.14 we already know that E is given by,
Consider an infinitesimally thin ring section of radius r and width dr. The area vector of this infinitesimally thin ring section is given by,
Hence the flux is given by,
SIR, HOW CAN YOU CONSIDER RING WITH SMALL CROSS SECTIONS IF IT WOULD HAVE BEEN DISC YOU WOULD HAVE CONSIDERED BUT IT IS NOT A DISC
ReplyDeleteQuestion is trying to ask how much flux is passing thru circle area ... Not thru any disk/any other body so dont misunderstand...!. Its just asking how many electric lines of force are passing thru circle area.( just like amount of water which passes thru a similar ring when you keep it in front of shower perpendicular to water flow) . Hope i helped !
DeleteAyush ur reply was not understandable to me.
DeleteBut field lines are virtual.
Deletesolid circle=disc
ReplyDeleteSir there is clearly mentioned that given aera is cricle of radius r.
ReplyDeleteNot a disk
Circle is also a disk
Deleteto those who are confused about circle and disc. read the last line of question it asks flus through circle area now as area is mentioned we can consider it as a disc
ReplyDelete