EASY
Earn 100

Two plates are 20 cm apart and the potential difference between them is 10 V. The electric field between the plates is

50% studentsanswered this correctly

Important Questions on Electrostatics

MEDIUM
A positive charge q is placed at the centre of a neutral hollow cylindrical conducting shell with its cross section as shown in the figure below.

Question Image

Which one of the following figures correctly indicates the induced charge distribution in the conductor (ignore edge effects).
HARD
Two uniformly charged spherical conductors A and B of radii 5 mm and 10 mm are separated by a distance of 2 cm. If the spheres are connected by a conducting wire, then in equilibrium condition, the ratio of the magnitudes of the electric fields at the surface of the sphere A and B will be
EASY
A parallel plate capacitor with plates of area 1 m2 each, are at a separation of 0.1 m. If the electric field between the plates is 100 N C-1, the magnitude of charge on each plate is: (Takeε0=8.85×1012 C2 N-1 m-2)
MEDIUM
Two capacitors C1 and C2 are charged to 120 V and 200 V respectively. It is found that by connecting them together the potential on each one can be made zero. Then:
HARD

Three concentric spherical shells are arranged as shown in the figure. The innermost and outermost spheres are connected to earth. If the middle sphere is given a charge q0. the charges induced in the innermost and outermost spheres respectively are

Question Image

EASY
The charge on a capacitor plate in a circuit, as a function of time, is shown in the figure:
Question Image
What is the value of current at t=4 s?
EASY

Given below are two statements.
Statement I : Electric potential is constant within and at the surface of each conductor.

Statement II : Electric field just outside a charged conductor is perpendicular to the surface of the conductor at every point.

In the light of the above statements, choose the most appropriate answer from the options give below.

HARD

Two identical parallel plate capacitors of capacitance each are connected in series with a battery of emf, E as shown. If one of the capacitors is now filled with a dielectric of dielectric constant k, the amount of charge which will flow through the battery is (neglect internal resistance of the battery)

Question Image

EASY

A hollow conducting sphere is placed in an electric field produced by a point charge placed at P as shown in figure. Let VA, VB, VC be the potentials at points A, B and C, respectively. Then

Question Image

EASY

A spherical conductor A is placed concentrically inside a hollow spherical conductor B. The charge +Q is given to A and B is earthed. Then the electric field is not zero

Question Image

HARD
A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect?
MEDIUM
The excess of pressure, due to surface tension, on a spherical liquid drop of radius R is proportional to
EASY
Two identical conducting spheres A and B carry an equal charges. They are separated by a distance much larger than their diameters, and the force between them is F. A third identical conducting sphere, C, is uncharged. Sphere C is first touched to A, then to B, and then removed. As a result, the force between A and B would be equal to:
EASY
A parallel plate capacitor is of area 6 cm2 and a separation 3 mm. The gap is filled with three dielectric materials of equal thickness (see figure) with dielectric constant K1=10, K2=12 and K3=14. The dielectric constant of a material which when fully inserted in above capacitor, gives same capacitance would be:

Question Image
MEDIUM

An electron enters a parallel plate capacitor with horizontal speed μ and is found to deflect by angle θ on leaving the capacitor as shown. It is found that tanθ=0.4 and gravity is negligible.

Question Image
If the initial horizontal speed is doubled, then tanθ will be:

HARD

A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 3 × 1 0 4  V/m , the charge density of the positive plate will be close to :

MEDIUM
A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system
EASY
Two charged spherical conductors of radius R1 and R2 are connected by a wire. Then the ratio of surface charge densities of the spheres σ1/σ2 is :
MEDIUM

Consider an initially neutral hollow conducting spherical shell with inner radius r and outer radius 2r. A point charge +Q is now placed inside the shell at a distance r2 from the center. The shell is then grounded by connecting the outer surface to the earth. P is an external point at a distance 2r from the point charge +Q on the line passing through the center and the point charge +Q as shown in the figure.

Question Image

The magnitude of the force on a test charge +q placed at P will be