As shown in the figure below, you exert a constant force F to the right on a con

Question

As shown in the figure below, you exert a constant force F to the right on a conducting rod of length 20.0 cm that can move without friction along a pair of conducting rails. The rails are connected at the left end by a resistor of resistance 30.0 , and we can assume that the resistance of each rail and the rod is negligible in comparison to the resistance of the resistor. There is a uniform magnetic field of magnitude 1.00 Tdirected into the page, and the rod begins from rest. Both the rails and the magnetic field extend a long way to the right. Note that you should be able to do this problem without a calculator.

(a) A long time after the rod begins to move, it reaches a constant speed of 2.00 m/s. When the rod reaches its maximum speed, what is the magnitude of the induced current in the loop?
_____A

In what direction is this induced current?

clockwise, or counterclockwise    

(b) What is the magnitude of the constant force F you exert on the rod for the rod to reach a maximum speed of 2.00 m/s?
_____N

Explanation / Answer

a) let the current be I

Voltage difference across rod is gven by B*v*L

I =B*v*L/R = 1*2*0.2/30 = 0.0133 ampere (counterclock wise)

b)

since the moving rod has constant velocity the net force on it should be zero

hence

B*I*L = F

F = 0.00266 Newton

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.