Questions

A line charge , $λ$ per unit length is pasted uniformly on to the rim of a wheel of mass m and radius R. The wheel has light non-conducting spokes and is free to rotate about a vertical axis as shown in figure. A uniform magnetic field extends over a radial region of radius r given by $B = - B_{0} \overset{\land}{k} (r \leq a; a < R) = 0$ (otherwise). What is the angular velocity of the wheel when this field is suddenly switched off?

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-2B0πa2rmRk∧

-B0πa2r3mRk∧

B0πa2λmRk∧

-B0πa2λmRk∧

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detailed solution

Correct option is D

Induced electric field (in clockwise sense):E=a22RdBdtI ω=∫τ dt⇒mR2ω=∫qERdt=∫qa22RdBdtRdt=λ2πR2Ra2R∫dB⇒ω=B0πa2λmR⇒ω→=-B0πa2λmRk∧(because clockwise sense)

Similar Questions

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