Condenser A has a capacity of 15 μF when it is filled with a medium of dielectric constant 15. Another condenser B has a capacity of 1 μF with air between the plates. Both are charged separately by a battery of 100 V. After charging, both are connected in parallel without the battery and the dielectric medium being removed. The common potential now is 

(1) 400 V

(2) 800 V

(3) 1200 V

(4) 1600 V

Four metallic plates each with a surface area of one side A are placed at a distance d from each other. The plates are connected as shown in the circuit diagram. Then the capacitance of the system between a and b is

(1) $\frac{3{\epsilon }_{0}A}{d}$

(2) $\frac{2{\epsilon }_{0}A}{d}$

(3) $\frac{2{\epsilon }_{0}A}{3d}$

(4) $\frac{3{\epsilon }_{0}A}{2d}$

In the given circuit if point C is connected to the earth and a potential of +2000 V is given to the point A, the potential at B is 

(1) 1500 V

(2) 1000 V

(3) 500 V

(4) 400 V

A finite ladder is constructed by connecting several sections of 2 μF, 4 μF capacitor combinations as shown in the figure. It is terminated by a capacitor of capacitance C. What value should be chosen for C such that the equivalent capacitance of the ladder between the points A and B becomes independent of the number of sections in between 

(1) 4 μF

(2) 2 μF

(3) 18 μF

(4) 6 μF

In an isolated parallel plate capacitor of capacitance C, the four surface have charges Q₁, Q₂, Q₃ and Q₄ as shown. The potential difference between the plates is 

(1) $\frac{Q_1+Q_2+Q_3+Q_4}{2C}$

(2) $\frac{Q_2+Q_3}{2C}$

(3) $\frac{Q_2-Q_3}{2C}$

(4) $\frac{Q_1+Q_4}{2C}$

For the circuit shown, which of the following statements is true 

(1) With S₁ closed, V₁ = 15 V, V₂ = 20 V

(2) With S₃ closed V₁ = V₂ = 25 V

(3) With S₁ and S₂ closed V₁ = V₂ = 0

(4) With S₁ and S₃ closed, V₁ = 30 V, V₂ = 20 V

Consider the situation shown in the figure. The capacitor \(A\) has a charge \(q\) on it whereas \(B\) is uncharged. The charge appearing on the capacitor \(B\) a long time after the switch is closed is: 

1. zero
2. \(\frac{q}{2}\)
3. \(q\)
4. \(2q\)

A capacitor of capacitance C₁ = 1 μF can withstand maximum voltage V₁ = 6kV (kilo-volt) and another capacitor of capacitance C₂ = 3 μF can withstand maximum voltage V₂ = 4 kV. When the two capacitors are connected in series, the combined system can withstand a maximum voltage of

(1) 4 kV

(2) 6 kV

(3) 8 kV

(4) 10 kV

The plates of a parallel plate condenser are pulled apart with a velocity v. If at any instant their mutual distance of separation is d, then the magnitude of the time rate of change of capacity depends on d as follows 

(1) 1/d

(2) 1/d²

(3) d²

(4) d

A fully charged capacitor has a capacitance ‘C’. It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity ‘s’ and mass ‘m’. If the temperature of the block is raised by ‘ΔT’, the potential difference ‘V’ across the capacitance is 

(1) $\frac{ms\Delta T}{C}$

(2) $\sqrt{\frac{2ms\Delta T}{C}}$

(3) $\sqrt{\frac{2mC\Delta T}{s}}$

(4) $\frac{mC\Delta T}{s}$