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Electromagnetism Induction of a Metal Bar

A metal bar with length L, mass m, and resistance R is placed on frictionless, metal rails that are inclined at an angle (Data) above the horizontal. The rails have negligible resistance. A uniform magnetic field of magnitude B is directed downward. The bar is released from rest and slides down the rails.
a) Is the direction of the current induced in the bar from a to b or from b to a?
b) What is the terminal speed of the bar?
c) What is the induced current in the bar when the terminal speed has been reached?
d) After the terminal speed has been reached, at what rate id electrical energy being converted to thermal energy in the resistance of the bar?
e) After the terminal speed has been reached, at what rate of work being done on the bar by gravity? Compare your answer to that in part (d)


Solution Preview

a.) By Flemming's right hand rule,
magnetic field B (index finger): down ward;
velocity v (thumb): downward along the wedge;

Hence, induced current i (middle finger): a to b --Answer

b.) At terminal speed (vt), along the plane
downward gravity force = upward ...

Solution Summary

This solution is provided in 175 words. It discusses Flemming's right hand rule to find induced current, as well as uses step-by-step equations to find the solution.