A vertical square loop of copper wire with sides of length 10 cm is falling as shown from a region where the magnetic field is horizontal and of magnitude 1.2 T into a region where the field is zero, as shown if figure. The wire has a diameter of 1 mm.

(i) Calculate the magnitude of the current round the loop in terms of the velocity v of fall, and indicate its sense.

(ii) What is the magnetic force acting on the loop, again expressed in terms of v?

(iii) If the velocity of fall reaches a steady value whilst the upper arm of the circuit remains in the field, calculate this velocity.

(The resistiivity of copper is 1.7 x 10^?8 ?m; the density is 8960 kg m^?3.)

R=1.2T R= 0