Electric Dipole
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Net dipole moment of a polar linear isotropic dielectric substance is not zero even in the absence of an external electric field.
Reason (R): In absence of an external electric field, the different permanent dipoles of a polar dielectric substance are oriented in random directions.
In the light of the above statements, choose the most appropriate answer from the options given below:
Show answer and solution
Answer: (c)
- Without an external field the permanent dipoles of a polar dielectric point in random directions (thermal agitation).
- Their vector sum is zero, so the net dipole moment is zero: (A) is false.
- (R) is a correct statement.
- So the answer is (c).