Electric Field Lines

Which of the following figures represent the electric field lines due to a single negative charge?

In figure, two positive charges q₂ and q₃ fixed along the y axis, exert a net electric force in the + x direction on a charge q1 fixed along the x-axis. If a positive charge Q is added at (x, 0), the force on q₁

(a)

(b)

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 ______.

If E_a be the electric field strength of a short dipole at a point on its axial line and E_e that on the equatorial line at the same distance, then:

1. An electrostatic field line is a continuous curve. That is, a field line cannot have sudden breaks. Why not?
2. Explain why two field lines never cross each other at any point?

Answer the following question.
Draw the pattern of electric field lines when a point charge +q is kept near an uncharged conducting plate.

Figure shows the electric field lines around three point charges A, B and C.

1. Which charges are positive?
2. Which charge has the largest magnitude? Why?
3. In which region or regions of the picture could the electric field be zero? Justify your answer.

(i) near A, (ii) near B, (iii) near C, (iv) nowhere.