Home
Class 12
PHYSICS
A parallel plate capacitor of plate area...

A parallel plate capacitor of plate area A and plate separation d is charged to potential difference V and then the battery is disconnected. A slab of dielectric constant K is then inserted between the plates of the capacitor so as to fill the space between the plates. If Q, E and W denote respectively, the magnitude of charge on each plate, the electric field between the plates (after the slab is inserted), and work done on the system, in question, in the process of inserting the slab, then

A

(a) `Q=(epsilon_0AV)/(d)`

B

(b) `Q=(epsilon_0KAV)/(d)`

C

(c) `E=(V)/(Kd)`

D

(d) `W=(epsilon_0AV^2)/(2d)[1-1/K]`

Text Solution

Verified by Experts

The correct Answer is:
A, C, D
As `C=epsilon_0/dA`

`=(epsilon_0A)/(d)xxV`
`C^'=(Kepsilon_0A)/(d)

`V^'=V/K`
`Q=(epsilon_0AV)/(d)=C^'V^'`
Q will remain same as no charge is leaving or entering the plates during the process of slab insertion
Now, `Q=C^'V^'=C^'E^'d`
`E^'=(Q)/(C^'d)=((epsilon_0AV)/(d))/((Kepsilon_0A)/(d))xx1/d=(V)/(Kd)`
Work done is the change in energy stored
`W=1/2CV^2-1/2C^'V^'2`
`=1/2(epsilon_0AV^2)/(d)-1/2(Kepsilon_0A)/(d)xx(V/K)^2` `[:' V^'=E^'d=V/K]`
`W=1/2(epsilon_0A)/(d)V^2[1-1/K]`
Promotional Banner

Topper's Solved these Questions

  • ELECTROSTATICS

    SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise Subjective Problems|2 Videos

  • ELECTROSTATICS

    SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise Comprehension Based Questions|2 Videos

  • ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENT

    SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise JEE Main And Advanced|107 Videos

  • MODERN PHYSICS

    SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise MCQ (One Correct Answer|1 Videos

Similar Questions

Explore conceptually related problems

A parallel - plate capacitor of plate area A and plate separation d is charged to a potential difference V and then the battery is disconnected . A slab of dielectric constant K is then inserted between the plate of the capacitor so as to fill the space between the plate .Find the work done on the system in the process of inserting the slab.

A parallel-plate capacitor of plate area A and plate separation d is charged by a ideal battery of e.m.f. V and then the battery is disconnected. A slab of dielectric constant 2k is then inserted between the plates of the capacitor so as to fill the whole space between the plates. Find the change in potential energy of the system in the process of inserting the slab.

In a parallel-plate capacitor of plate area A , plate separation d and charge Q the force of attraction between the plates is F .

Figure shows a parallel plate capacitor with plate area A and plate separation d . A potential difference is being applied between the plates. The battery is then disconnected and a dielectric slab of dieletric constant K is placed in between the plates of the capacitor as shown. The electric field in the gaps between the plates and the electric slab will be

Figue shows a parallel plate capacitor with plate area A and plate separation d . A potential difference is being applied between the plates. The battery is then disconnected and a dielectric slab of dieletric constant K is placed in between the plates of the capacitor as shown. The electric field in the dielectric slab is

A parallel plate capacitor of capacitance C_(0) is charged with a charge Q_(0) to a potential difference V_(0) and the battery is then disconnected Now a dielectric slab of dielectric constant k is inserted between the plates ofcapacitor. The dimensions of the slab are such that it completely fills the space between the plates, then :

A parallel plate capacitor of plate area A and plates separation distance d is charged by applying a potential V_(0) between the plates. The dielectric constant of the medium between the plates is K. What is the uniform electric field E between the plates of the capacitor ?

A parallel plate capacitor of plate are A and plate separation d is charged by a battery of voltage V. The battery is then disconnected. The work needed to pull the plates to a separation 2d is

A parallel plate capacitor having plate area A and separation between the plates d is charged to potential V .The energy stored in capacitor is ....???