ELECTRICAL DEPARTMENT NOTICE BOARD

	Question bank  (4Th semester)
	A C Machines [ subject code : 2140906]
1	Explain the construction and working principle of  Polyphase Induction Motor
2	Explain OC & SC test of  Polyphase Induction Motor
3	Explain the losses & power stage of  Polyphase Induction Motor
4	Explain the Equivalent circuit of a 3-phase induction motor with necessary diagrams & equations.
5	Derive an equation for mechnical power developed in 3-phase induction motor. Also derive the condition for maximum mechnical power developed.
6	Explain the importance of Circle diagram of Polyphase Induction Motor in detail.
7	Explain the need of starter for AC motor. Draw and Explain the circuit diagram of any one Starter for 3-Phase Induction Motor.
8	Explain the effect of unbalance voltage and variation in frequency on the performance of 3-Phase Induction Motor.
9	Explain the Rotating magnetic field in three phase induction motor.
10	State the difference between DOL starter and Star-delta starter.
11	Explain how by inserting resistance in the rotor circuit of a slipring induction motor the starting current of the motor can be limited.
12	Explain the phenomenon of cogging and crawling in induction motor.
13	Explain performance of 3-phase I.M. for change in supply frequency with constant supply voltage.
14	Derive the condition of max. torque of Induction Motor.Also explain factors affecting max. torque condition.
15	Derive the equation of  torque of three phase Induction Motor under running condition.
16	Derive the equation of  torque of three phase Induction Motor at starting.
17	Derive the condition of max. torque of three phase Induction Motor at starting.
18	Derive the condition of max. torque of three phase Induction Motor under running condition.
19	Explain the losses & power stage for three phase induction motor.
20	Explain different types of harmonic torque in induction motor.
21	Explain the construction and working principle of  Alternator.
22	What are the different excitation systems used in synchronous machine
23	What is  SCR in synchronou machine ?, explain the factor affecting on it in detail.
24	Compare the methods for finding voltage regulation of Alternator.
25	Explain the different effect for failour in synchronizing the alternators.
26	Explain the different methods for synchronizing the alternators.
27	Derive the equation of induced emf for a synchronous generator with & without harmonic effect.
28	List different methods for finding voltage regulation of an alternator and explain any one method.
29	State the conditions necessary for paralleling alternators. Explain one dark and two bright lamp method with necessary electrical circuit diagram.
30	Explain concept of pitch factor and distribution factor in case of an alternator. How these values change with harmonics.
31	What is armature reaction? Explain the effect of armature reaction at different power factor on the terminal voltage of an alternator.
32	Derive emf equation of alternator. Explain distribution factor with effect of harmonics.
33	Explain the direct load test for finding voltage regulation of three phase alternator .
34	Explain Armature reaction and its effects at different power factor in Alternator.
35	Explain the two reaction theory of salient pole machine in detail with phasor diagram.
36	Explain the construction and working of synchronous motor.
37	Explain the effect of change of load on the performance of 3-phase synchronous motor.
38	Describe the experimental setup to obtain the v-curves of a synchronous motor.
39	Why synchronous motor is not self starting? Explain the methods of starting of synchronous motor.
40	Briefly explain the operation of a synchronous machine with change in excitation and constant mechanical power input. Draw the corresponding phasor diagrams.
41	Derive the expression for the input and output power developed by synchronous motor. Also derive the maximum input and output power developed by synchronous motor.
42	Explain “V” curves and inverted “V” curves for synchronous motor.
43	Explain the two reaction theory of salient pole synchronous machine.
44	Explain hunting of synchronous machines and methods of its prevention.
45	Explain the effect of varying excitation at constant load on synchronous motor.
46	Explain the Equivalent circuit of a 1-phase induction motor with necessary diagrams & equations.
47	Explain the double field revolving theory of single phase AC motor with necessary equations.
48	Explain , why 1-phase induction motor is not self starting ?
49	List out the different types of 1-phase induction motor, explain any one in detai.
50	Explain the construction and working principle of AC series motor with neat diagram. Also state its application.
51	Explain the construction and working principle of shaded-pole motor with neat diagram. Also state its application.
52	Explain the construction and working principle of split-phase motor with neat diagram. Also state its application.
53	Explain the construction and working principle of capacitor start motor with neat diagram. Also state its application.
54	Explain the construction and working principle of capacitor run motor with neat diagram. Also state its application.
55	Explain the construction and working principle of capacitor start-capacitor run motor with neat diagram. Also state its application.
56	Explain the construction and working principle of Universal motor with neat diagram. Also state its application.
57	Explain the torque-speed characteristics of different types of 1-phase motor
58	What are the disadvantages of a 1-phase induction motor when compared with 3-phase induction motor.
59	Explain OC & SC test of  1-phase Induction Motor
60	Write the Applications of all types of 1-phase motors.