Capacitors Numerical Class XII

 

 Question 1

A parallel plate air capacitors has plate area 0.2 m2 and has separation distance 5.5 mm. Find

(a) Its capacitance when capacitor is charged to a potential difference of 500 volts

(b) Its charge

(c) Energy stored in it

(d) Force of attraction between the plates

Question 2

Consider a system of capacitors where two parallel plate air capacitors each of capacitance C are connected in series to a battery of EMF ξ. Now one of the capacitor is filled uniformly with a dielectric of dielectric constant K. What would happen to electric field strength of that capacitor and what would be the change in electric field strength?  Calculate the amount of charge that flows through the battery?

Question 3

A spherical capacitor has charges + Q and - Q on its inner and outer conductors. Find the electric potential energy stored in the capacitor?

Question 4

Find the capacitance of an isolated spherical conductor of radius r1 surrounded by an adjacent concentric layer of dielectric with dielectric constant K and outside radius r2.

Question 5

In a parallel plate air capacitor having plate separation 0.05mm, an electric field of 4 x 104 V/m is established between the plates. After the removal of the battery a metal plate of thickness t=0.02 mm is inserted between the plates of the capacitor. Find

A)Potential difference across capacitor before the introduction of metal plates.

B)Potential difference across capacitor after the introduction of metal plates.

C)Potential difference across capacitor if dielectric slab with dielectric constant K=3 and same thickness were inserted in place of metal plate.