A dielectric slab of area `A` and thickness `d` is inderted between then plates of a capaitor of area `2A` with constant speed `upsilon` as shown in. Dustance between the plates is (d).
.
The capacitor is connected to a battery of emf `E`. The current in the ciruit varies with time as.

Options

A.
B.
C.
D.

Answer

D

Explanation

`C(t)=(epsi_(0)A)/(d)=K((vtxxb)epsi_(0))/(d)+((l-vt)bepsi_(0))/(d)`
`Q(t)=CV=(Kvbepsi_(0))/(d)t+(bepsi_(0)l)/(d)-(bepsi_(0)vt)/(d)`
`I=(dq)/(dt)=(Kvbepsi_(0))/(d)-(bepsi_(0)V)/(d)`
`I=((K-I)vbepsi_(0))/(d)=` const