A circular coil of mean radius of 7 cm and having 4000 turns is rotated at the rate of 1800 revolutions per minute in the earth's magnetic field (B=0.5 gauss), the emf induced in coil will be

Step-by-step solution

Here: n=4000, B=0.5 10⁻⁴ ~Wb / m ^2 Rate of rotation of coil =1800 rev / min = 1800 60 =30 rev / sec aligned & =2 f=2 30=60 rad / s , & r=7 ~cm =0.07 ~m aligned Now area of coil A= r^2= (0.07)^2=49 10⁻⁴ ~m ^2 Now the maximum energy induced is aligned e & =B A n & =0.5 10⁻⁴ 49 10⁻⁴ 4000 60 & =0.58 ~V aligned