Dielectric

Ans:3
Please explain how to solve this sum. Please show working. Is energy stored in dielectric?



@asthareddy Why is U1/U2= C1/C2? Here we assume—there is no battery connected to the capacitor while inserting the dielectric (since nothing is mentioned). So charge means constant but voltage will vary.
If U=Q²/(2C), then U1/U2= C2/C1, isn't it? Please explain.

@anag
it will not matter. go through above dervation @KdsDhaniksamba

@kdsdhaniksamba
@asthareddy Can you please explain why
V2= (C1)²× V/(C1+C2)² ? V is common potential after redistribution of charge into capacitors C1 & C2?
I am unable to derive it:
According to my working, V2= (C1+C2)V/C2.

@anag here it's not mentioned slab is placed after it was charged slab is placed initially it it was placed after capacitor get charged it will be mentioned

@kdsdhaniksamba Can you please explain why
V2= (C1)²× V/(C1+C2)² ?What are we suppose to conserve here to arrive at this equation?
I am unable to derive it. Please help.

@anag just watch my solution above
As they are in series q is constant v1/v2=c1/c2
And v1+v2=v solve these two equations

@kdsdhaniksamba Since they are in series, q is constant. Hence,
q= C1V1= C2V2
So =› C1/C2= V2/V1, isn't it?