You need to design a 60.0-Hz ac generator that has a maximum emf of 5500 V. The generator is to contain a 150-turn coil that has an area per turn of 0.85 m 2 . What should be the magnitude of the magnetic field in which the coil rotates?

So magnetic field will be equal to 0.1144 T  

Explanation:

We have given frequency f = 60 Hz

Maximum emf e = 5500 volt

Number of turns N = 150

Area

Emf generated in ac generator is given

For maximum emf

So maximum emf will be equal to

So magnetic field will be equal to 0.1144 T

unlike poles attract