Question

A conductor of $3\text{m}$ length, is moving with a speed of ${10}^2\text{m/s}$. It is moving in a direction, perpendicular to its length, as well as to a magnetic field of ${10}^{-3}\text{T}$. The force required to move it with this constant speed is -

• A. $0.3\text{N}$
• B. $0.9\text{N}$
• C. $0$
• D. $3\times {10}^{-3}\text{N}$

Answer 1

The correct option is C $0$

Motional emf will be induced in it $(E=Bvl)$.

But as the loop is not closed, no current will flow through it and hence, no magnetic field force will act upon it.

Hence, option $\left(C\right)$ is the correct answer.