Electric Charges & Fields | MCQs Quiz-02

The magnitude of the electric field due to a point charge object at a distance of 4 m is 9 N/C. From the same charged object, the electric field of magnitude 16 N/C will be at a distance of-

A point charge q is kept at a distance r from an infinitely long straight wire with charge density λ. The magnitude of the electrostatic force experienced by charge q is-

Assertion- Electric lines of force cross each other.
Reason- Electric field at a point superimposes to give one resultant electric field.

Some point charges are enclosed by four closed surfaces S₁, S₂, S₃ and S₄ as shown in the figures. The ratio of areas of these surfaces are 1:2:3:4. The electric flux through the surface

Assertion- Work done in moving a charge around a closed path in an electric field is always zero.
Reason- Electrostatic force is a conservative force.

Two similar spheres having +Q and -Q charges are kept at a certain distance. The force F acts between the two charges. If at the middle of two spheres, another similar sphere having +Q charge is kept, then it experiences a force in magnitude and direction as-

An electric dipole of dipole moment 2 x 10^-8 C m in a uniform electric field experiences a maximum torque of 6 x 10^-4 Nm. The magnitude of electric field is-

(A) 2.2 x 10³ Vm^-1

(B) 1.2 x 10⁴ Vm^-1

(C) 3 x 10⁴ Vm^-1

(D) 4.2 x 10³ Vm^-1

A point P lies at a distance x from the midpoint of an electric dipole on its axis. The electric potential at point P is proportional to-

(A) x^-2

(B) x^-3

(C) x^-4

(D) x^-1/2