Question

Question 1.26: Which among the curves shown in Fig. 1.35 cannot possibly represent electrostatic field lines? (a) (b) (c) (d) (e)

Class 12 - Physics - Electric Charges And Fields Electric Charges And Fields Page-48

Answer 1

I would like to advice to answer this question, if you understand properties of lines of force. let's start which is wrong and which are correct?

(a) it is wrong , because electric field lines must be normal to the surface of conductor outside it. but here you can see sum lines of force do not normal to the surface of conductor.

(b) it is wrong because field lines cannot start or originate form the negative charge and also cannot end or submerge into positive charge.

(c) it is correct because field lines originate from positive charge and if two same charge are placed close to each other then electric lines of force are repel each other like shown in figure.

(d) it is wrong because electric field lines never intersect each other.

(e) it is wrong, because electric field lines cannot form closed loops.

Answer 2

(a) The field lines showed in (a) do not represent electrostatic field lines because field lines must be normal to the surface of the conductor.

(b) The field lines showed in (b) do not represent electrostatic field lines because the field lines cannot emerge from a negative charge and cannot terminate at a positive charge.

(c) The field lines showed in (c) represent electrostatic field lines. This is because the field lines emerge from the positive charges and repel each other.

(d) The field lines showed in (d) do not represent electrostatic field lines because the field lines do not intersect each other.

(e) The field lines showed in (e) do not represent electrostatic field lines because electric field lines do not form  closed loops.