Final answer:
The question involves understanding the operation of a single-phase induction motor under initial and normal conditions, focusing on current, voltage, and power dissipation.
Step-by-step explanation:
The student's question pertains to the operation of a single-phase induction motor and its parameters at different operating conditions. When the motor is initially turned on with an emf of 48.0 V and a resistance of 0.400 Ω, it draws a current of 120 A, resulting in power dissipation of 5.76 kW as heat. However, under normal operating conditions, when there is a back emf of 40.0 V, the voltage across the coils is reduced to 8.0 V, yielding a current of 20 A and power dissipation of 160 W, which is manageable for the motor. These calculations are crucial for understanding the starting and running characteristics of induction motors, as well as their thermal management.