An AC induction machine has six poles and is designed for 60-Hz, 240-V (rms) operation. When the machine operates with 10 percent slip, it produces 60 N-m of torque.
a. The machine is now used in conjunction with an 800-W constant power load. Determine the speed and slip of the machine when used with the above-mentioned load.
b. If the machine has an efficiency of 89 percent, what minimum rms current is required for operation with the load of part a?
Hint: You may assume that the speed-torque curve is approximately linear in the region of interest.