JEE Mains · Physics · STD 12 -6. Electromagnetic induction
A coil is placed in a time varying magnetic field. If the number of turns in the coil were to be halved and the radius of wire doubled, the electrical power dissipated due to the current induced in the coil would be: (Assume the coil to be short circuited.)
- A Halved
- B Quadrupled
- C The same
- D Doubled
Answer & Solution
Correct Answer
(D) Doubled
Step-by-step Solution
Detailed explanation
\(P =\frac{\varepsilon^{2}}{ R }=\frac{\left( NA \frac{ dB }{ dt }\right)^{2} \times A _{ C }}{\rho \ell}\) \(P ^{\prime}=\frac{\left(\frac{ NA }{2} \frac{ dB }{ dt }\right)^{2} \times 4 A _{ C }}{\rho \ell / 2}\) \(\Rightarrow P ^{\prime}=2 P\)
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