The question is incomplete. The complete question is:
A 500-turn coil with a 0.250 m2 area is spun in the Earth’s 5.00 × 10−5 T field, producing a 12.0 kV maximum emf. (a) At what angular velocity must the coil be spun? (b) What is unreasonable about this result? (c) Which assumption or premise is responsible?
Answer:
ω=1.92 × 106 rad/s
Step-by-step explanation:
Emfo= 12.0×10^3 V
N= 500 turns
A= 0.250 m^2
B= 5.00×10^-5
ω=??????
From
Emfo= NABω
ω= Emfo/NAB
ω= 12.0×10^3/500×0.250×5.00×10^-5
ω=1.92 × 106 rad/s
b) This angular velocity is unreasonably high, it is very much higher than a value that can be obtained for any mechanical system.
c) The unreasonable assumption or premise that a peak voltage as high as 12.0kV may be obtained.