Answered>Order 33

A metal bar of mass m slides frictionlessly on two parallel conducting rails a

distance d apart. A resistor R is connected across the rails and a uniform magnetic field

B, pointing into the page, fills the entire region.

(a) If the bar moves to the right at speed v, what is the current in the circuit? In what

direction does it flow? What is the power dissipated at R?

(b) What is the magnetic force on the bar? In what direction?

(c) What is the rate of work done by this force? Compare this with the power dissipated

at R.