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KVPY2020PhysicsElectromagnetic Induction

A conducting rod, with a resistor of resistance R , is pulled with constant speed v on a smooth conducting rail as shown in figure. A constant magnetic field B → is directed into the page. If the speed of the bar is doubled, by what factor does the rate of heat dissipation across the resistance R change?

Options

  1. A0
  2. B2
  3. C2
  4. D4

Correct answer

D. 4

Step-by-step solution

E m f = V B L I = V B L R Heat = I 2 R = V 2   B 2   L 2 R Given V 1 = 2   V So H 1 H = 4

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