Electrostatics Question 304
Question: A point $ Q $ lies on the perpendicular bisector of an electrical dipole of dipole moment $ p $ . If the distance of $ Q $ from the dipole is $ r $ (much larger than the size of the dipole), then electric field at $ Q $ is proportional to [CBSE PMT 1998; JIPMER 2001, 02]
Options:
A) $ {{p}^{-1}} $ and $ {{r}^{-2}} $
B) $ p $ and $ {{r}^{-2}} $
C) $ {{p}^{-1}} $ and $ {{r}^{-2}} $
D) $ p $ and $ {{r}^{-3}} $
Show Answer
Answer:
Correct Answer: D
Solution:
$ E _{equatorial}=\frac{kp}{r^{3}} $ i.e. $ E\propto p $ and $ E\propto {{r}^{-3}} $