Question

The number of turns in th coil of an $ac$ generator is $5000$ and the area of the coil is $0.25m^2$. The coil is rotated at the rate of $100$ cycles/s in a magnetic field of $0.2T$. The peak value of emf generated is nearly:

• A. $786kV$
• B. $440kV$
• C. $220kV$
• D. $157.1kV$

Answer 1

The correct option is D $157.1kV$

As given,

$N=5000turns$

$B=0.2w/m^2$

$A=0.25m^2$

$V=1000se{c}^{-1}$

as $E_0=NBAW$

$=5\times {10}^3\times 2.5\times 0.25\times 100\times 2\times 3.14$

$=3.14\times 0.5\times {10}^{6}V$

$E_0=157kV$