Question

An A.C. generator consists of a coil of 100 turns arid cross-sectional area of 3 $m^2$, rotating at a constant angular speed of 60 radian/sec in a uniform magnetic field of 0.4 T. The resistance of the coil is 500 ohm. What is the maximum power dissipation in the coil?

• A. 518.4 W
• B. 1296W
• C. 259.2W
• D. Zero

Answer 1

Answer: (B)

1296W

$N=100,A=3m^2,\omega =60rad/s$

$B=0.4TR=500\Omega$

As induced emf is given by $=NBA\omega sin\omega t$

Max emf $e_0=NBA\omega =100\times 0.4\times 3\times 60$

$=7200$ Volt

Induced current ( max )$I_0=\frac{e_o}{R}=7200/500=18A$

Power $=e_0{I}_0$ $7200\times 18=1.296\times {10}^{3}watt$