posted by Phy .
A simple motor has N=250 turns of wire on a coil measuring 12 cm \times \, 4 cm. It's resistance is R=10 ohms. The magnetic field is B=1 T.
(a) How much current (in Ampere) in the coil is needed to produce a maximum torque of 40 Nm?
b) What maximum EMF (in Volts) is needed to drive the motor at 50 Hz if the current is constant?