Electrostatics Question 315
Question: An electric dipole of moment $ \overrightarrow{p} $ placed in a uniform electric field $ \overrightarrow{E} $ has minimum potential energy when the angle between $ \overrightarrow{p} $ and $ \overrightarrow{E} $ is [UPSEAT 2004]
Options:
A) Zero
B) $ \frac{\pi }{2} $
C) $ \pi $
D) $ \frac{3\pi }{2} $
Show Answer
Answer:
Correct Answer: A
Solution:
$ U=-PE\cos \theta $
It has minimum value when q = 0o i.e. $ {{(U _{P})} _{\min }}=-PE\times \cos 0^{o}=-PE $
