Question

Why do electric field lines not form closed loops?
A) It is always directed towards a positive charge from a negative charge
B) It is always directed from positive charge to negative charge
C) It is always directed away from a negative charge
D) It can be in any random direction

Answer 1

Hint: Electric field lines never form closed loops since electric field lines originate at one polarity of charge and end at the opposite polarity of charge. We will use this property to determine why electric field lines do not form closed loops.

Complete step by step answer
Electric field lines are lines that help us in visualizing the direction of the electric field for a given system of a charge.
Electric field lines always start from a positive charge and hence they always diverge away from the negative charge. The electric field lines then converge on negative charges which mean they always end on negative charges.
Since electric field lines originate and terminate on charges of opposite polarity, electric field lines can never form closed loops as to form a closed loop, the electric field lines must originate and end at the same charge.

However electric field lines are directed from positive charges to negative charges so option (B) is the correct choice.

Even if we had two similar charges in a system, the electric field lines will be stretched towards infinity in one direction and will never form a closed loop.

Note
The direction of electric field lines is a convention that is the choice of electric field lines originating from positive charges and terminating at negative charges is a convention and we can draw them the other way around. Regardless, they cannot form closed loops since the lines end and begin on charges of opposite polarity. Electric field lines are also only helpful for visualizing and they don’t exist in reality.