Question

An a.c. generator consists of a coil of $100$ turns and cross-sectional area of $3 \,m^{2}$, rotating at a constant angular speed of $60$ radian/sec in a uniform magnetic field of $0.04 \,T$. The resistance of the coil is $500$ ohm. What is the maximum power dissipation in the coil?

• A. $518.4\,W$
• B. $1036\,W$
• C. $259.2\,W$
• D. Zero

Answer 1

Answer: (A)

$518.4\,W$

Answer 2

Here, $N=100, A=3\,m^{2}, \omega=60\,rad \,s^{-1}, B=0.04\,T$, $R=500\,\Omega$ Max. power dissipation $=\varepsilon_{eff\cdot I_{eff}} =\frac{\varepsilon_{0}}{\sqrt{2}}\cdot\frac{I_{0}}{\sqrt{2}}=\frac{I_{0}^{2}R}{2}$ $=\frac{\left(1.44\right)^{2}\times500}{2}$ $=518.4\,W$