Question

In a certain region of space, electric field is along the z-direction throughout. The magnitude of electric field is, however not constant but increases uniformly along the positive z-direction at the rate ${10}^{5}V/m.$ The force and the torque experienced by a system having a total dipole moment equal to ${10}^{-7}C-m$ in the negative z-direction is given by respectively.

• A. 0.01,0
• B. 0.02,0
• C. 0,0.01
• D. None of the above

Answer 1

The correct option is A 0.01,0

$z$ direction positive rate $={10}^{5}V/m$

torque $=$ M $\times$ $E$

$={10}^5\times {10}^{-7}$

$=0.01cm$