Electrostatics ...

Two small charged spheres A and B have charges 10 µC and 40 µC, respectively, and are held at a separation of 90 cm from each other. At what distance from A would the electric intensity be zero?

If the distance between two point charges is made 3 times, the new force on either charge will be _______.

Directions: The following question has four choices out of which ONLY ONE is correct.
three charges -q, Q, -q are placed at a equal distance on a staright line. if the total potential energy of the system is zero, then what is the ratio of Q:q ?

A parallel plate capacitor has a voltage of 5 V between the two plates separated by 4 microns (1 micron = 10^-6 m). What is the electric field between the capacitor plates?

Directions: The following question has four choices out of which ONLY ONE is correct.

two point charges 2x10^-6C & 4x10^-6C are 12 cm apart. what is the amount of work done to bring the charges 3 cm closer?

Two charges of equal magnitudes at a distance 'r' exert a force 'F' on each other. If the charges are halved and the distance between them is doubled, then the new force acting on each charge is

Two wires A and B, made of same material and having their lengths in the ratio 6 : 1 are connected in series. The potential differences across the wires are 3 V and 2V, respectively. If r_A and r_B are the radii of A and B respectively, then is

Two charged spheres separated by a distance 'd' exert some force 'F' on each other. If they are immersed in a liquid of dielectric constant 4, then what is the force exerted, if all other conditions are the same?

The electric potential at a point on the axis of an electric dipole depends upon the distance r (>> a) of the point from centre of the dipole as

The electric potential due to a small electric dipole at a large distance r, from the center of the dipole is proportional to

The potential at a point P, which is forming a corner of a square of side 93 mm with charges Q₁ = 33 nC, Q₂ = -51 nC, Q₃ = 47 nC located at the other three corners, is nearly

An electron enters uniform electric field maintained by parallel plates and of value 'E' V m^-1 with a velocity ' v ' ms^-1. The plates are separated by a distance 'd' metre. What is the acceleration of the electron in the field?

The angle between electric field and equipotential surface is :

A and B are two identically spherical charged bodies which repel each other with a force F when kept at a finite distance apart. A third uncharged sphere of the same size is brought in contact with sphere B and removed. It is then kept at the mid-point of the distance between A and B. What is the magnitude of force on C?

A capacitor of capacitance 50 µF charged with a potential of 3000 V is connected to a patient and every 2 minutes a pulse is sent. What is the power delivered?

A charge of magnitude 3e and mass 2m is moving in an electric field, . The acceleration imparted to the charge is

Who discovered the charge on an electron?

A flux of 0.2 Wb, linked with a coil having 50 turns, is reduced to zero in one second. What is the average emf induced in the coil?

In the case of a charged metallic sphere, potential (V) changes with respect to distance (r) from the centre as:

A. (1)
B. (2)
C. (3)
D. (4)

What is the electric potential at the center of a square in given figure ?

Bulb B1 (100 W - 250 V) and bulb B2 (100 W - 200 V) are connected across 250 V. What is potential drop across B₂?

In a Van de Graff generator, the maximum potential difference is 10⁶ V. The dielectric strength of air is 3 x 10⁶ V/m. The minimum radius of the metallic shell 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:

The work done in placing a charge of 8 x 10^-18 C on a condenser of capacity 100 µF is:

Three charges, i.e. - q₁, + q₂ and - q₃ are placed as shown in the figure. The x-component of the force on - q₁ is directly proportional to