Electrostatics ...

According to superposition of electric fields 

The work done in carrying a charge q around a circle of radius r with a charge Q at the centre is 

A parallel plate capacitor of capacitance 5 and plate separation 6 cm is connected to a 1 V battery and charged. A dielectric of dielectric constant 4 and thickness 4 cm is introduced between the plates of the capacitor. The additional charge that flows into the capacitor from the battery is

Two point charges –q and +q are located at points (0, 0, – a) and (0, 0, a), respectively. What is the electric potential at point (0, 0, z)?

Two insulating plates are both uniformly charged in such a way that the potential difference between them is V₂ – V₁ = 20 V (plate 2 is at a higher potential). The plates are separated by a distance d = 0.1 m and can be treated as infinitely large. An electron is released from rest on the inner surface of the first plate. What is its speed when it hits the second plate?
(Given: e = 1.6 x 10^–19 C, m = 9.11 x 10^–31 kg) 

For charges q₁ and q₂  separated by a distance R the magnitude of the electrostatic force is given by 

The capacitance of a sphere of radius R₁ is increased 3 times when it is enclosed by an earthed sphere of radius R₂. The ratio R₂/R₁ is

In charging by Induction 

The figure below shows four plates separated from one another by a distance d and each having an area A. What is the capacitance between P and Q?

In the network shown in the figure given below, C₁ = 6  and C = 9 . The equivalent capacitance between points P and Q is

A capacitor of capacitance C₁ = C is charged to a voltage V. It is then connected parallel to a series combination of two uncharged capacitors of capacitances C₂ = C and C₃ = C. The charge that will flow through the connecting wires is

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, then the potential difference V across the capacitor will be

A parallel plate capacitor is maintained at a certain potential difference. When a dielectric slab of thickness 3 mm is introduced between the plates, the plate separation has to be increased by 2 mm in order to maintain the same potential difference between the plates. The dielectric constant of the slab is

A capacitor of capacitance 4  is charged to 80 V and another capacitor of capacitance 6  is charged to 30 V. When they are connected together, the energy lost by the 4  capacitor is

Electric field at a point is defined as 

Four large metal plates are located a small distance apart from one another as shown in the figure. The extreme plates are earthed by a conductor, while a potential difference V is applied to the internal plates. Find the magnitudes of the electric fields between the neighbouring plates.

The electric potential V (in volts) varies with x (in metres) according to the relation V = 5 + 4x². The force experienced by a negative charge of 2 x 10^-6 C, located at x = 0.5 m, is

Directions: In the following question, statement - 1 (Assertion) is followed by statement - 2 (Reason). Select the appropriate answer.

Statement - 1:  If an electron is moved from P to Q, its potential energy increases.



Statement - 2: Potential at Q is less than that at P.

Two identical capacitors, having plate separation d₀, are connected parallel to each other across a point 'A' as shown in the figure. Charge Q is imparted to the system by connecting a battery across the points 'A' and 'B', and then the battery is removed. If the first plate of the first capacitor and the second plate of the second capacitor started moving with constant velocity u₀ towards the left, then find the magnitude of current flowing in the loop.

The unit of charge is