question_answer

The electric field intensity \[\overrightarrow{E}\], due to an electric dipole of moment \[\overrightarrow{P}\], at a point on the equatorial line is:

A)  parallel to the axis of the dipole and opposite to the direction of the dipole moment \[\overrightarrow{P}\]

B)  perpendicular to the axis of the dipole and is directed away from it

C)  parallel to the dipole moment

D)  perpendicular to the axis of the dipole and is directed towards it

Correct Answer: A

Solution :

Consider an electric dipole consisting of two point charges \[-q\] and \[+q\] separated by a small distance \[AB=2a\]with centre at O, As shown in figure, on equatorial line, the resultant electric field \[\overrightarrow{E}\] of \[{{\overrightarrow{E}}_{1}}\] and \[{{\overrightarrow{E}}_{2}}\] is parallel to the axis of the dipole but opposite to the direction of the dipole moment p as it is directed from negative charge to positive charge.