Class 12 Electrostatic Potential And Capacitance CBSE Questions & Answers

Four capacitors, each of capacitance 50 \(\mu {\rm{F}}\) are connected as shown in the figure. If the voltmeter reads 100 V, the charge on each capacitor is

Three condensers of capacity 2 \(\mu {\rm{F}}\) , 4 \(\mu {\rm{F}}\) and 8 \(\mu {\rm{F}}\) respectively, are first connected in series and then connected in parallel. The ratio of the equivalent capacitance in the two cases will be

A capacitor of capacitance C = 2 \(\mu {\rm{F}}\) is connected as shown in the figure. If the internal resistance of the cell is 0.5\(\Omega \) , the charge on the capacitor plates is

Two parallel plate capacitors of capacitances C and 2C are connected in parallel and charged to a potential difference V by a battery. The battery is then disconnected and the space between the plates of capacitor C is completely filled with a material of dielectric constant K = 3. The potential difference across the capacitors now becomes

In the network shown in the figure, C1 = 6 \(\mu {\rm{F}}\) and C = 9 \(\mu {\rm{F}}\). The equivalent capacitance between points P and Q is

Three capacitors, each of capacitance C = 3 mF, are connected as shown in the figure. The equivalent capacitance between points P and S is

A parallel plate air filled capacitor shown in the Fig. (a) has a capacitance of 2 \(\mu {\rm{F}}\) . When it is half filled with a dielectric of dielectric constant k = 3 as shown in Fig. (b), its capacitance becomes

A parallel plate air filled capacitor shown in Fig. (a) has a capacitance of 2 \(\mu {\rm{F}}\) . When it is half filled with a dielectric of dielectric constant k= 3 as shown in Fig. (b), its capacitance becomes

A \({\rm{2}}\mu {\rm{F}}\) capacitor C1 is charged to a voltage 100 V and a 4 \(\mu {\rm{F}}\) capacitor C2 is charged to a voltage 50 V. The capacitors are then connected in parallel. What is the loss of energy due to parallel connection?

A parallel plate capacitor of plate area A has a charge Q. The force on each plate of the capacitor is

A capacitor of capacitance C is fully charged by a 200 V supply. It is then discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat \({\rm{2}}.{\rm{5}} \times {\rm{1}}{0^{\rm{2}}}{\rm{J k}}{{\rm{g}}^{ - {\rm{1}}}}{\rm{K}}{^{ - {\rm{1}}}}\) and of mass 0.1 kg. If the temperature of the block rises by 0.4 K, what is the value of C?

The capacitance of a parallel plate capacitor is 5 \(\mu {\rm{F}}\) . When a glass slab of thickness equal to the separation between the plates is introduced between the plates, the potential difference reduces to 1/8 of the original value. The dielectric constant of glass is

The dielectric constant K of an insulator can be

If the diameter of earth is \({\rm{128}} \times {\rm{1}}{0^{\rm{2}}}\)km, then its capacitance will be

A charged sphere of radius a is put in contact with another uncharged sphere of radius b. Show that ratio of original surface density to that of final surface density of charge on first sphere is