# A short-circuited coli Is placed In a time-varying magnetic field. Electrical power is dissipated due to the current induced In the coil. If the number of turns were to be quadrupled and the coil radius halved, the electrical power dissipated would be (a) halved (b) the same (c) doubled ( d ) quadrupled

$Power \ \ P=\frac{e^{2}}{R}, \\ hence e=-\left(\frac{d \varphi}{d t}\right) where \varphi=N B A : \\e=-N A\left(\frac{d B}{d t}\right) \\ Also R \propto \frac{1}{r^{2}} where R= resistance, r= radius, l= Length : \\P \propto \frac{N^{2} r^{2}}{l} \Rightarrow \frac{P_{1}}{P_{2}}=1$

### Preparation Products

##### Knockout NEET Sept 2020

An exhaustive E-learning program for the complete preparation of NEET..

₹ 15999/- ₹ 6999/-
##### Rank Booster NEET 2020

This course will help student to be better prepared and study in the right direction for NEET..

₹ 9999/- ₹ 4999/-
##### Knockout JEE Main Sept 2020

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 12999/- ₹ 6999/-
##### Test Series NEET Sept 2020

Take chapter-wise, subject-wise and Complete syllabus mock tests and get in depth analysis of your test..

₹ 4999/- ₹ 2999/-