The figure below shows two resisters, both with resistance R = 10 Ohm, connected

Question

The figure below shows two resisters, both with resistance R = 10 Ohm, connected to an open switch S, and two frictionless metal rails that are separated by a distance l = 0.25 m. The rails are in a region with constant magnetic field B = 2.0 T, and a rod is moving with a constant velocity v = 10 m/s to the right on the rails a) Since the velocity is constant, an external force F must act on the rod. Determine the magnitude and direction of this force. b. The switch is now closed. What is this force F now?

Explanation / Answer

induced emf = B L v

e = 2 x 0.25 x 10 = 5 volt

I = e / R = 5 / 10 = 0.50 A

force, F = IL x B

F = 0.50 x 0.25 x 2 = 0.25 N
to the left

(B) now R' = R R / (R + R) = R/2 = 5 ohm

I = 5/ 5 = 1 A

F = 1 x 0.25 x 2 = 0.50 N

to the left

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---