A metallic rod of mass per unit length 2. is lying horizontally on a smooth inclined plane which makes an angle of 45º with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction B is acting on it in the vertical direction. The minimum current flowing in the rod to keep it stationary is:
(1) \(\frac{\lambda g}B\)
(2) \(\frac{\sqrt 2\,\lambda g}B\)
(3) \(\frac{\lambda g}{\sqrt2\,B}\)
(4) \(\frac{2\lambda g}B\)