Drives and Controls for Automation

CIA I

Questions

PART A

1. Draw the Mechanical Characteristics of D.C Series Motor. (2)

2. What are the two types of 3 phase induction motor? (2)

3. Why an induction motor never runs at synchronous speed? (2)

4. Why single phase induction motor is not self starting? (2)

PART B

(i) Draw and explain the different modes of torque-slip characteristics

of a 3-phase Induction motors. (5)

(ii) Compare the mechanical characteristics and applications of DC motors. (7)

(iii) Explain Back EMF in DC motor. (3)

(Or)

(i) Discuss about different types of Electrical Drives and its applications. (5)

(ii) Explain the working of Slip-Ring 3 phase Induction motor with circuit diagram. (7)

(iii) A 3 phase 4 pole 50 Hz induction motor runs at 1460 r.p.m. Find its percentage slip. (3)