Parallel Plate Capacitor

IMPORTANT

Parallel Plate Capacitor: Overview

This Topic covers sub-topics such as Parallel Plate Capacitors, Fringing of the Field and, Force between Plates of a Charged Parallel Plate Capacitor

Important Questions on Parallel Plate Capacitor

EASY
IMPORTANT

The two plates of a parallel plate capacitor are 5 mm apart. A slab of a dielectric, of thickness 4 mm is introduced between the plates with its faces parallel to them. The distance between the plates is adjusted so that the capacitance of the capacitor becomes equal to its original value. If the new distance between the plates equal 8 mm, what is the dielectric constant of the dielectric used?

HARD
IMPORTANT

On charging a parallel plate capacitor to a potential V, the spacing between the plates is halved, and a dielectric medium of  εr=10  is introduced between the plates, without disconnecting the d.c. source. Explain, using suitable expressions, how the
(i) capacitance,
(ii) potential difference and
​(iii) energy stored in the capacitor change.

EASY
IMPORTANT

If two similar plates, each of area A having surface charge densities   +σandσ are separated by a distance d in air, write expressions for the potential difference between the plates.

EASY
IMPORTANT

The distance between two plates of a capacitor is d and its capacitance is C1, when air is the medium between the plates. If a metal sheet of thickness 2d3 and of the same area as plate is introduced between the plates, the capacitance of the capacitor becomes C2 . The ratio C2C1 is

MEDIUM
IMPORTANT

A parallel plate capacitor with plate area A and plate separation d is filled with a dielectric material of dielectric constant K=4. The thickness of the dielectric material is x, where x<d.

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Let C1 and C2 be the capacitance of the system for x=13d and x=2d3, respectively. If C1=2 μF, the value of C2 is _____ μF.

MEDIUM
IMPORTANT

As shown in the figure, two parallel plate capacitors having equal plate area of 200 cm2 are joined in such a way that ab. The equivalent capacitance of the combination is xε0F. The value of x is _____.

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EASY
IMPORTANT

In a parallel plate capacitor of capacitance 4 µF, if a dielectric plate (K=3) with width equal to half of the width of the capacitor is introduced, the value of capacitance will become :

MEDIUM
IMPORTANT

A metallic slab of thickness 2d3 and area of surface same as that of plates of capacitor of capacitance C1 is inserted parallel to plates of capacitor such that its new capacitance becomes equal to C2. If d is the width between the two plates then C2C1 is equal to

EASY
IMPORTANT

Area of one side of each plate is A and separation between consecutive plates is d. Emf of the battery connected is V. The charge on plate 2 is 

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EASY
IMPORTANT

 A slab of material having dielectric constant K=1.5 has the same area as the plates of a parallel plate capacitor but has thickness 34 of plate separation introduced between the plates of the capacitor having capacitance C. On introducing slab, capacity becomes factor of

EASY
IMPORTANT

A parallel plate capacitor of capacitance C is charged to a potential V by a battery. Q is the charge stored on the capacitor. Without disconnecting the battery, the plates of the capacitor are pulled apart to a larger distance of separation.

What changes will occur in each of the following quantities? Will they increase, decrease or remain the same? Give an explanation in each case.

(a) Capacitance

(b) Charge

(c) Potential difference

(d) Electric field

(e) Energy stored in the capacitor

EASY
IMPORTANT

A capacitor consists of two parallel plates, with an area of cross-section of 0.001 m2, separated by a distance of 0.0001 m. If the voltage across the plates varies at the rate of 108 V/s, determine the value of displacement current through the capacitor.

EASY
IMPORTANT

A parallel plate capacitor with plate area A and plate separation d, with vacuum between the plates has a capacitance C0.
The space between the plates is filled with two slabs of the same area but thicknesses d4 and 3d4 made of material of dielectric constant 2 and 4, respectively. The capacitance of the capacitor is now.
 

MEDIUM
IMPORTANT

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Four identical metal plates each having area A, are arranged as shown in figure. Find the equivalent capacity of the structure between A and B.
 

HARD
IMPORTANT

Two large parallel conducting plates are given charge Q1 and Q2 respectively as shown in the figure. Find the charge flown through the switch after the switch is closed.

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HARD
IMPORTANT

A capacitor of capacitance C consists of two large parallel metal plates. The coefficient of linear expansion of the metal is α. What is the change in capacitance if the temperature of the plates rises by T, while the gap between the plates is kept fixed?

MEDIUM
IMPORTANT

A parallel plate capacitor of capacitance 500pF and plate area 0.05 m2 is filled with porcelain K=6.5. A potential difference of 200 V is applied. The following observations are recorded. Mark the one which is not correct.

MEDIUM
IMPORTANT

A parallel plate capacitor have capacitance C, when area of each plate is halved and distance between plates is doubled, what happened with capacitance when dielectric 2.5 Introduced between them.

EASY
IMPORTANT

A parallel plate capacitor have capacitance C. If area of the plate doubled and distance between plates also doubled, then the capacitance will be

MEDIUM
IMPORTANT

The Plates Of A Parallel Plate Capacitor Are Charged By A Battery And The Battery Is Disconnected After The Charging. Now, The Plates Are Placed As Shown In The Figure. Then (Plates Are Not Parallel To Each Other)

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