Capacitors and Capacitance

IMPORTANT

Capacitors and Capacitance: Overview

This topic covers concepts, such as Capacitor and Its Capacitance, Relation between Charge on a Conductor and Change in Its Potential, Factors Affecting Capacitance, Dielectric Strength of an Insulator, Unit of Capacitance, Use of Capacitor, etc.

Important Questions on Capacitors and Capacitance

HARD
IMPORTANT

Calculate final charge on 1μF capacitor:

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MEDIUM
IMPORTANT

In a capacitor which is initially charged such that the left plate of capacitor has charge +Q and the right plate has zero charge at time t=0 s. The total charge on the right plate after closing the switch will be

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EASY
IMPORTANT

Find the potential drop across the capacitor when the circuit given below achieves steady-state.

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MEDIUM
IMPORTANT

Calculate the charge on a capacitor of capacitance C=2.0±0.1 μF and charged to a voltage V=20±0.2 V.

EASY
IMPORTANT

When the charge on a capacitor increases keeping geometry the same

MEDIUM
IMPORTANT

A parallel plate condenser is filled with two dielectrics as shown in the figure. The area of each plate is A m2 and the separation is d metre. The dielectric constants are K1and K2 respectively. Its capacitance in farad will be-

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HARD
IMPORTANT

Effective capacitance of parallel combination of two capacitor C1 and C2 is 10 μF. When we inserted a dielectric slab between the plates the new capacitance will be ( dielectric constant K1=2, K2=4)

 

MEDIUM
IMPORTANT

A parallel plate capacitor of capacitance 15 μF. A dielectric slab K=2 of thickness 1 mm is inserted between the plates. Then new capacitance is given by-

MEDIUM
IMPORTANT

A dielectric slab of thickness d is inserted in a parallel plate capacitor whose negative plate is at X=0 and the positive plate is at X=3d. The slab is equidistant from the plates. The capacitor is given some charge. As X goes from 0 to 3d then,

[a] The electric potential increases at first, then decreases and again increases.
[b] The electric potential increases continuously.
[c] The direction of the electric field remains the same
[d] The magnitude of the electric field remains the same

MEDIUM
IMPORTANT

A capacitor is charged using a battery, and the battery is withdrawn later on. Now a dielectric slab is introduced between the capacitor plates then the correct statement is-

HARD
IMPORTANT

A parallel plate air capacitor is charged by connecting its plates to a battery. Without disconnecting the battery, a dielectric is introduced between its plates. As a result-

MEDIUM
IMPORTANT

The value of a capacitor formed by a thin metallic foil is 2 μF. The foil is folded with a layer of paper having a thickness of 0.015 mm. The dielectric constant of the paper is 2.5 and its breadth is 40 mm. The length of the foil used is-

MEDIUM
IMPORTANT

A sheet of aluminium is inserted in the air gap of a parallel plate capacitor without touching any of the two plates of the capacitor. The capacitance of the capacitor is-

EASY
IMPORTANT

A parallel plate capacitor is first charged and then disconnected from the battery and then a dielectric slab is introduced between the plates. The quantity that remains unchanged is

MEDIUM
IMPORTANT

The distance between the plates of a parallel plate capacitor is d. A copper plate of the same area but thickness d2 is placed between the plates then the new capacitance will become-

MEDIUM
IMPORTANT

In the following figure, the charge on each condenser in the steady state will be-

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EASY
IMPORTANT

A parallel plate capacitor is charged and then isolated. On increasing the plate separation-

EASY
IMPORTANT

A capacitor of 6 μF is charged to such an extent that the potential difference between the plates becomes 50 V. The work done in this process will be,

EASY
IMPORTANT

4 μF capacitor is charged to 400 V and then its plates are joined through a resistor of resistance 1 . The heat produced in the resistor is,

EASY
IMPORTANT

What are the charges stored in the 1 μF and 2 μF capacitors in the circuit below, once the currents become steady

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