Electrostatics Question 705
Question: If the dipole of moment $ 2.57\times {{10}^{-17}}cm $ is placed into an electric field of magnitude $ 3.0\times 10^{4}N/C $ such that the fields lines are aligned at $ 30{}^\circ $ with the line joining P to the dipole, what torque acts on the dipole?
Options:
A) $ 7.7\times {{10}^{-13}}Nm $
B) $ 3.855\times {{10}^{-13}}Nm $
C) $ 3.855\times {{10}^{-15}}Nm $
D) $ 7.7\times {{10}^{-15}}Nm $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ \tau =( 2.57\times {{10}^{-17}}Cm )( 3.0\times 10^{4}\frac{N}{C} )( \frac{1}{2} ) $
$ =3.855\times {{10}^{-13}}Nm. $
