CGPET 2019 Solved Paper

Given, situation can be shown in figure below R Applying, kirchhoff's voltage law,
⇒L

dI

dt

+IR=E⇒

dI

dt

+

IR

L

=

E

L

We know that, integration factor
IF=e∫

R

L

t
or e(

R

L

)t.I=∫e(

R

L

)t.

E

L

⇒e

R

L

tI=

E

L

.

L

R

e

R

L

t⇒I=

E

L

.

L

R

So, the current in the circuit after a long time will be
I=

E

R