Electrodynamics...

The displacement of a charge Q in the electric field = e₁+ e₂+ e₃ is = a+ b. The work done is

A parallel plate condenser with a dielectric of dielectric constant, K between the plates has a capacity, C and is charged to a potential, V volts. The dielectric slab is slowly removed from between the plates and then reinserted. The net work done by the system in this process is:

Two equally charged identical metal spheres A and B repel each other with a force F. The spheres are kept fixed with a distance r between them. A third identical, but uncharged sphere C is brought in contact with A and then placed at the mid-point of the line joining A and B. The magnitude of the net electric force on C is :

A spherical capacitor consists of an inner sphere of diameter 6 cm and an outer sphere of diameter 10 cm. The space between the two concentric spheres is filled with a medium of dielectric constant 80. What is the capacitance of the capacitor?

A pendulum bob of mass 80 milligrams, which is carrying a charge of 2 x 10^-8 C, is at rest in a uniform horizontal electric field of 20,000 V/m. What angle () will it make with the vertical?

Three point charges of 1 C, 2 C and 3 C are placed at the corners of an equilateral triangle of side 1 m. The work done (in joules) in bringing these charges to the vertices of a smaller similar triangle of side 0.5 m is

A charged particle is suspended in equilibrium in a uniform vertical electric field of intensity 20000 V/m. If the mass of the particle is 9.610 x 10^-16 kg, the charge on it and excess number of electrons on the particle respectively are (g = 10 m/s²)

Three charges 1 C, 1 C and 2 C are respectively kept at the vertices A, B and C of an equilateral triangle ABC of side 10 cm. The resultant force on the charge at C is

An insulator plate is passed through the plates of a capacitor as shown. The current

Eight drops of mercury of equal radii, each having the same charge, combine to form a big drop. The capacitance of this big drop as compared to that of each smaller drop is

If 1000 drops of water of same radius r and same charge q combine to form a big drop, then how many times is the potential of the big drop relative to the potential of a small drop?

The top of the atmosphere is about 400 kV with respect to the surface of Earth corresponding to an electric field that decreases with altitude. Near the surface of Earth, the field is about 100 Vm^-1. Still, we do not get an electric shock as we step out of house into an open space because (assume the house to be a steel cage so that there is no field inside)

A spherical capacitor has an inner sphere of radius 9 cm and an outer sphere of radius 10 cm. The outer sphere is earthed. Assuming that there is air in the space between the spheres, what is the capacitance of the capacitor?

The potential at a point x (measured in m) due to some charges situated on the x-axis is given by V(x) = 20/(x² - 4) volts. The electric field E at x = 4 m is given by

A capacitor having capacitance of 1 µF in air is filled with two dielectrics as shown. How many times will the capacitance increase?

Two point charges 3 × 10^-6 C and 8 × 10^-6 C repel each other by a force of 6 × 10^-3 N. If each of them is given an additional charge of -6 × 10^-6 C, then the force between them will be

A charged particle q moving with speed v is shot towards another charged particle Q, which is held stationary. It approaches Q up to a closest distance r and then returns. If q was given a speed of 2v, what will be the closest distance approached by this charge?

If the inward flux and outward electric flux from a closed surface respectively are 8 × 10³ units and 4 × 10³ units, then what is the net charge inside the closed surface?

An electric charge of 10^-3 μC is placed at the origin (0, 0) of an X-Y coordinate system. Two points A and B are at (, ) and (2, 0), respectively. The potential difference between the points A and B will be

The electric flux for Gaussian surface A that encloses the charged particles in free space is (given q₁ = - 14 nC, q₂ = 78.85 nC,q₃ = - 56 nC)

A thin spherical conducting shell of radius R has a charge q. Another charge Q is placed at the centre of the shell. The electrostatic potential at point P, at a distance R/2 from the centre of the shell, is

A hollow metal sphere has an inner radius of 10 cm and an outer radius of 20 cm. This hollow metal sphere carries no net electric charge. A small solid metal bell of radius 1.0 cm is located at the centre of the hollow sphere. The metal ball carries a positive charge of 200 nC. What is the electric charge (nC) on the outer surface of the hollow metal sphere?

A parallel plate air capacitor is charged to a potential difference of V volts. After disconnecting the charging battery, the distance between the plates of the capacitor is increased using an insulating handle. As a result, the potential difference between the plates

Two point charges 2q and 8q are placed at a distance r apart. Where should a third charge -q be placed between them, so that the electric potential energy of the system is minimum?

Two identical capacitors, each of capacitance 5 µF, are charged to potentials 2 kV and 1 kV. Their negative ends are connected together. When the positive ends are also connected together, what is the loss of energy of the system?