KVPY2016PhysicsElectromagnetic Induction
A conducting bar of mass m and length moves on two frictionless parallel rails in the presence of a constant uniform magnetic field of magnitude B directed into the page as shown in the figure . The bar is given an initial velocity v ₀ towards the right at t =0 . Then the
Options
- AInduced current in the circuit is in the clockwise direction
- BVelocity of the bar decreases linearly with time
- CDistance the bar travels before it comes to a complete stop is proportional to R
- DPower generated across the resistance is proportional to .
Correct answer
C. Distance the bar travels before it comes to a complete stop is proportional to R
Step-by-step solution
F = iB a = iB m = B . A d dt = B ( dx dt ) =( B v ) i = / R = B v R a = ( B v R ) B m a = B ² ² Rm v a = v dv dx v . dv dx = B ² ² Rm v dv = B ² ² Rm d x v = B ² ² Rm ^ X ^ [ X = vRM B ^ ² ]