The rectangular frame in Figure is free to rotate about the axis A-A on the horizontal shaft. The frame is 10 cm long and 6 cm wide and the rods that make up the frame have a mass per unit length of 20 g/cm. A uniform magnetic field B?= 0.2 T is directed as shown. A current may be sent around the frame by means of the wires attached at the top.

(a) If no current passes through the frame, what is the period of this physical pendulum for small oscillations?

(b) If a current of 8.0 A passes through the frame in the direction indicated by the arrow, what is then the period of this physical pendulum?

(c) Suppose the direction of the current is opposite to that shown. The frame is displaced from the vertical by some angle ?. What must be the magnitude of the current so that this frame will be in equilibrium?

Transcribed Image Text:

Wire OA