Figure shows a conducting rod PQ in contact with metal rails RP and SQ which are 0.257 apart in i uniform magnetic field of flux density 0.4T acting perpendicular to the plane of the paper. Ends R and S are connected through a 5 `Omega` resistance. What is the emf when the rod moves to the right with a velocity of 5 `ms^(-1)`? What is the magnitude and direction of the current through the 5 `Omega` resistance? If the rod PQ moves to the left with the same speed, what will be the new current and its direction?

Explanation

`|e|= B lv = 0.4 xx 0.25 xx 5= 0.5V`
Current, `I= (|e|)/(R )= (0.5V)/(5 Omega)= 0.1A`
Applying Fleming.s right hand rule, the current in the rod shall flow from Q to P. If the rod moves to the left with the same speed, then the current of 0.1A will flow from P to Q