An armature coil consists of 20 turns of wire, each of area $A=0.09 m^2$ and total resistance 15 Ω. It rotates in a magnetic field of 0.5 T perpendicular to the axis of rotation at a constant frequency $\frac{150}{π}$ Hz. The value of maximum emf produced in the coil is:

270 V

The correct answer is Option (2) → 270 V

The maximum emf ($ε_{max}$) induced in a rotating coil is given by the formula -

$ε_{max}=N.B.A.ω$

where,

N, Number of turns = 20

B, Magnetic field = 0.5 T

A, Area of each turn = $0.09m^2$

f, rotational frequency = $\frac{150}{π}Hz$

Angular frequency, $ω=2πf$

$=2π×\frac{150}{π}$

= 300 rad/s

$∴ ε_{max}=20×0.5×0.09×300$

$=270V$