Electrostatics Question 311
Question: An electric dipole has the magnitude of its charge as q and its dipole moment is p. It is placed in a uniform electric field E. If its dipole moment is along the direction of the field, the force on it and its potential energy are respectively [CBSE PMT 2004]
Options:
A) $ 2q\cdot E $ and minimum
B) $ q\cdot E $ and $ p\cdot E $
C) Zero and minimum
D) $ q\cdot E $ and maximum
Show Answer
Answer:
Correct Answer: C
Solution:
In the given condition angle between $ \vec{p} $
and $ \vec{E} $ is zero.
Hence potential energy $ U=-pE\cos 0=-pE=\min . $
Also in uniform electric field $ F _{net}=0 $ .
