Electric force and fields

An isolated point charge particle produces an electric field E at a point 3 m away from it.

The distance of the point at which the field is E/4 will be

• 2m

• 3m

• 4m

• 6m

An object has charge of 1 C and gains 5.0 × 10¹⁸ electrons. The net charge on the object becomes

• –0.80 C

• +0.80 C

• +1.80 C

• +0.20 C

A negatively charged object X is repelled by another charged object Y. However an object Z is attracted to

object Y. Which of the following is the most possibility for the object Z?

• Positively charged only

• Negative charged only

• Neutral or Positively charged only

• Neutral or Negative charged only

The magnitude of the electric field due to a point charge object at a distance of 4.0 m is

9 N/C. From the same charged object the electric field of magnitude, 16 N/C will be at a

distance of

• 1m

• 2m

• 3m

• 6m

An electric dipole of dipole moment

2 x 10^-8C-m in a uniform electric field experiences a maximum torque of

6 x 10^–4 N-m.

The magnitude of electric field is

• 2.2 x 10³ Vm^–1

• 1.2 x 10⁴ Vm^–1

• 3 x 10⁴ Vm^–1

• 4.2 x 10³ Vm^–1

In an experiment three microscopic latex spheres are sprayed into a chamber and became charged with

charges +3e, +5e and −3e respectively. All the three spheres came in contact simultaneously for a moment

and got separated. Which one of the following are possible values for the final charge on the spheres?

• +5e , –4e , +5e

• +6e , +6e , –7e

• –4e , +3.5e , +5.5e

• +5e , –8e , +7e

A point charge is situated at an axial point of a small electric dipole at a large distance from it. The charge

experiences a force F. If the distance of the charge is doubled, the force acting on the charge will become

• 2F

• F/2

• F/4

• F/8

Name of the physical quantity whose S.I. unit is JC^-1

. Is it a scalar or a vector quantity?

An electric dipole placed in a non-uniform electric field can experience

• a force but not a torque.

• a torque but not a force.

• always a force and a torque.

• neither a force nor a torque.

If the net electric flux through a closed surface is zero, then we can infer

• No net charge is enclosed by the surface.

• Uniform electric field exists within the surface.

• Electric potential varies from point to point inside the surface.

• Charge is present inside the surface.