Question 72 of 153
is a vertical smooth long loop having a total resistance where is parallel to and separation between them is . A constant magnetic field perpendicular to the plane of the loop exists in the entire space. A rod of length and mass is made to slide down from rest under the gravity as shown in figure. The terminal speed acquired by the rod is acceleration due to gravity)
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Answer: (C) \(\frac{m \mathrm{~g} R}{B^2 l^2}\)
As rod CD slides down with velocity , it cuts magnetic field lines.
Induced EMF:
Induced current in the circuit:
Magnetic force on the rod (upward, by Lenz's law):
At terminal velocity, acceleration is zero.
Applying Newton's second law:
Induced EMF:
Induced current in the circuit:
Magnetic force on the rod (upward, by Lenz's law):
At terminal velocity, acceleration is zero.
Applying Newton's second law:
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