In the figure a 740 cm rod is moving on rails 695 cm apart w

In the figure, a 74.0 cm rod is moving on rails 69.5 cm apart with a speed of 1 m/s in a 0.90 T magnetic field. The resistance of the current path (U-shaped conductor and the bar) is 64.0 Ohm. Calculate the induced emf. Calculate the current in the U-shaped conductor at the moment. Calculate the external force needed to keep the rod\'s velocity constant.

Solution

a)

Induced emf

E=BLV =0.9*0.74*1

E=0.666 Volts

b)

Induced current

I=E/R =0.666/64

I=10.4 mA

c)

Force

F=BIL =0.9*0.0104*0.74

F=6.93 mN