problem 1: Describe what an Electric Drive is and describe different types of Electric drives.
a) Derive an expression for the temperature rise of equipment in terms of heating constant.
b) Derive an expression for the time dependent temperature as the electrical apparatus cools, in terms of the cooling time constant.
problem 3: Describe various types of loads based on active, passive torque, speed-torque and output-time.
a) Describe what do you mean by load equalization and how it is achieved?
b) A 250V D.C. shunt motor with constant field excitation drives a load, the torque of which varies as the square of the speed.
The armature current is 20A, when the motor is running at 500rpm. Find out the percentage reduction in the speed of the motor when a resistance of 20Ω is joined in series with the armature. Neglect the losses in the motor.
problem 5: Describe different speed control methods for both A.C., D.C. Motors.
a) Describe in brief about different types of Resistance heating.
b) Describe in brief about different types of dielectric heating.
problem 7: Describe in brief about different types of Induction heating.
problem 8: prepare down the applications of induction heating. What are the factors to be considered for inductor design in the induction heating?