Embibe Experts Solutions for Exercise 5: EXERCISE 2.5

In a cylindrical capacitor with plate radii $a$ and $\mathrm{b},$ the potential difference between the plates is $\mathrm{V}.$ The electric field between the plates at a radial distance $r$ from axis is

Two parallel plates have area $A$ and separation $d.$ They are given charges $q_1$ and $q_2.$ They repel each other by a force

The heat generated in the circuit after closing the switch is

A parallel plate capacitor is charged by a battery of emf $V$ volts. Work done by battery is $W.$ Gain in energy of capacitor is $U$ and heat dissipated in lead wires is $H.$ Then

A capacitor of capacitance $C$ is charged to a potential difference $V$ from a cell and then disconnected from it. A charge $+Q$ is now given to its positive plate. The potential difference across the capacitor is now

A charge of $1\mu \mathrm{C}$ is given to one plate of a parallel plate capacitor of capacitance $0.1\mu \mathrm{F}$ and a charge of $2\mu \mathrm{C}$ is given to the other plate. Find the potential difference developed between the plates.

A parallel plate air capacitor is to be constructed which can store $12\mu \mathrm{C}$ of charge when operated at $1200 \mathrm{V}.$ If dielectric strength of air is $3\times {10}^6 \mathrm{V} {\mathrm{m}}^{-1},$ the minimum plate area of the capacitor required is

Plate $A$ of a parallel plate air filled capacitor is connected to a spring having force constant  $\text{'}K$ and plate $B$ is fixed. They rest on a frictionless table top as shown in figure. If $+q$ and $-q$ charges are given to $A$ and $B$ very slowly then elongation in spring will be