Flag Electric Current> dielectrics in a capacitor...
question mark

There are two capacitor plates and two different dielectric media are filled in such a way that one side of the diagonal is filled with dielectric medium with constant k1 and the other side with a constant k2. This is an IITJEE question and the soln gives the answer as

eA( k1*k2) (ln( k1)-ln(k2))/ d( k1-k2)

But if we substitute k1=k2=k, we get the result as an indeterminate form which doesn't make sense.

Instead, why can't we divide it into 4 parts equal ( 2 lines thru the middle along length and breadth) in such a way that two diagonally opp parts have capacitance identical to that of the full capacitor and the other two parts are either fully filled with k1 or with k2.?

doing it in that method, the answer comes as

eA (k1k2)^0.5 / d.

Here applying the boundary condn k1=k2=k also works..so why is this wrong???

Aishwarya Prem Renu , 13 Years ago
Grade
anser 2 Answers
Chetan Mandayam Nayakar

If you encounter an indeterminate form, then use L Hospitals Rule

Last Activity: 13 Years ago
Aishwarya Prem Renu

This is a physics problem. In capacitors! Nothing to do with limits! 

Last Activity: 12 Years ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments