The armature of an ac generator has 100 turns. Each turn is a rectangular loop measuring 8.0 cm by 12 cm. The generator has a sinusoidal voltage output with an amplitude of 24 V. If the magnetic field of the generator is 250 mT,
a) With what frequency does the armature turn?
b) If you double the B and cut ω in half, how does this affect the amplitude?