A generator has 200 turns of wire on a coil of radius 200cm

A generator has 200 turns of wire on a coil of radius 2.00cm. What rotational speed is necessary to produce an emf of amplitude 4.50 V if the magnetic field in the region of the coil is 0.180T?

e= NABw

w=e/NBA

= 4.50/(200*0.180*0.001257)

99.43 rad/s ( ****HOW TO CONVERT TO rpm***)

THE ANSWER IS 950rpm

Solution

Induced emf

E=NBAW

=>W=E/NBA =4.5/200*0.18*pi*0.02²

W=99.47 rad/sec

1 rad/sec =(60/2pi) rpm

W=99.47*(60/2pi)=950 rpm