A conducting bar slides frictionless on the two parallel horizontal rails 69.0 cm apart. The bar and rails form the closed circuit having a resistance of 0.670 ohm, supposed to be constant all through the motion. The circuit is positioned in a uniform vertical magnetic field of 0.415 T perpendicular to the plane of circuit. The bar is pulled at a constant speed of 32.0 cm/s all along the rails. Determine the magnitude of the force needed to pull the bar?
Determine the rate of Joule heating in the circuit?