Electrostatics Question 294
Question: The distance between the two charges $ +q $ and $ -q $ of a dipole is $ r $ . On the axial line at a distance $ d $ from the centre of dipole, the intensity is proportional to [CPMT 1977]
Options:
A) $ \frac{q}{d^{2}} $
B) $ \frac{qr}{d^{2}} $
C) $ \frac{q}{d^{3}} $
D) $ \frac{qr}{d^{3}} $
Show Answer
Answer:
Correct Answer: D
Solution:
Field along the axis of the dipole $ E=\frac{1}{4\pi {\varepsilon _{0}}}.\frac{2p}{d^{3}}=\frac{1}{4\pi {\varepsilon _{0}}}.\frac{2(q\times r)}{d^{3}}; $
$ E\propto \frac{qr}{d^{3}} $
