Electrostatics Question 712
Question: An electric dipole, consisting of two opposite charges of $ 2\times {{10}^{-6}}C $ each separated by a distance 3 cm is placed in an electric field of $ 2\times 10^{5}N/C. $ Torque acting on the dipole is
Options:
A) $ 12\times {{10}^{-1}}N-m $
B) $ 12\times {{10}^{-2}}N-m $
C) $ 12\times {{10}^{-3}}N-m $
D) $ 12\times {{10}^{-4}}N-m $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Charger (q) $ =2\times {{10}^{-6}}C, $
Distance [d]$ =3cm=3\times {{10}^{-2}}m $
and electric field (E) $ =2\times 10^{5}N/C. $
Torque $ ( \tau )=q.d. $
$ E=( 2\times {{10}^{-6}} )\times ( 3\times {{10}^{-2}} )\times ( 2\times 10^{5} ) $
$ =12\times {{10}^{-3}}N-m. $
