Question

5 pts A rotating generator has a square planar coil consisting of 100 turns. The coil rotates 60 times per second in a magnetic field of 1.25T and yields a peak output voltage of 300 V. What is the length of one side of the coil? O 0.64 cm O 8.0 cm O 64 cm 80 cm O 120 cm

Answer 1

ANSWER: 2nd option, 8 cm.

EXPLANATION: By using the concept of magnetic flux through the loop and the emf induced in the coil we can solve this as follows...

We know that NAB Cono flux through the coil is, 9 = NB. D Where a is the magnetic flux number of turns is area vector of the wil. B is the magnetic field Vector. w is angular velocity of the coil, then and > W= oft area of the - where is the angle between coil and B. Wt Now, from coquation , emf induced at the coil is, dQ NAB at Be cause, we 7 2 Sin we So, NAB W e e given that feak output voltage is 3oor, so from equation ② will have maximum valere when sin we = maximum that is sin wt = 1 So e = 300 = NAB W given, B = 1.25 T, N=1

Now, given that coil rotates Go rotation in one second. Angular velocity és W. degree /sec. Go хат so, w= t t 60x2x180 degree /sec = 1 376.8 rad (sec. te = [:- 11 rad 1° 180° that is 3.14 1ชิญ from 3 300 = 100 x 1.25* à x 376.8 where, Area = A= a where one side length of the stuare. a is =) ă= 3 2 m 1.25 X 376.8 ñ a 11 0.08 m 8 cm ~ a