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 of `10^(5)NC^(-1)m^(-1)` . What are the force and torque experienced by system having a total dipole moment equal to `10^(-7)`Cm in the negative z-direction?

Options

A. `10^(-4)N` along `+z`-direction
B. `10^(-4)N` along `-z`-direction
C. `10^(-2)N` along `-z`-direction
D. `10^(-2)N` along `+z`-direction

Answer

c

Explanation

Net force on dipole `F_(n et)=qdE`
`F_(n et)=(qdz)((dE)/(dZ))=p((dE)/(dZ))`
`=10^(-7)xx(10^(5))=10^(-2)N` along `-z`-direction