Electrostatics Question 292
Question: An electric dipole consisting of two opposite charges of $ 2\times {{10}^{-6}}C $ each separated by a distance of $ 3cm $ is placed in an electric field of $ 2\times 10^{5} $ N/C. The maximum torque on the dipole will be [MP PMT 1987]
Options:
A) $ 12\times {{10}^{-1}}Nm $
B) $ 12\times {{10}^{-3}}Nm $
C) $ 24\times {{10}^{-1}}Nm $
D) $ 24\times {{10}^{-3}}Nm $
Show Answer
Answer:
Correct Answer: B
Solution:
Maximum torque = pE $ =\text{ 2}\times \text{1}{{0}^{\text{6}}}\times \text{3}\times \text{1}{{0}^{\text{2}}}\times \text{2}\times \text{1}{{0}^{\text{5}}}=\text{ 12}\times \text{1}{{0}^{\text{3}}}N-m $ .