Level 6 Graduate Diploma in Engineering (9210-01) - City & Guilds

Induction motors
23. Explain how electrical energy input is converted to mechanical energy in an induction motor.
24. Explain the difference between two types of induction motors: squirrel cage and wound rotor
machines.
25. Explain how force is exerted on the rotor conductor
26. Explain what is meant by slip of induction motor.
27. Express the rotor speed in terms of slip and synchronous speed.
28. Explain electromagnetic field interaction in induction machine
29. Develop an expression for the shaft torque developed
30. Describe losses in an induction motors.
31. Sketch ‘exact equivalent circuit’ and ‘approximate equivalent’ for an induction machine.
32. Analysis of induction motor with the help of equivalent circuit.
33. Determine equivalent circuit parameters of induction motor with the help of locked rotor and no
load tests.
34. Derive an expression for the electromagnetic torque developed in terms of emf, rotor
impedance, synchronous speed and slip.
35. Derive expressions for staring torque and the maximum torque.
36. Draw the characteristic of induction motor and explain those characteristic.
37. Explain the methods of staring three phase induction motor.
38. Explain the speed control of induction motor by varying frequency and pole pair number.
39. Explain the differences between the motoring, generating and breaking modes of operation of
three phase induction machines.
40. Derive the torque versus speed curve for the induction for all three modes of generation.
41. Select three phase induction motor for a given application
42. Solve problems related to operation and maintenance of three phase induction motors
43. Explain common faults associated with three phase induction motors
Single phase induction motors
44. Explain the operating principles of single-phase induction machine.
45. Explain the starting and running performance of single-phase induction machine.
46. Determine the value of capacitance for the maximum torque.
47. Explain the area of use of single-phase induction motors.
48. Select single phase induction motor for a given application
49. Solve problems related to operation and maintenance of single phase induction motors
50. Explain common faults associated with single phase induction motors
DC machines
51. Explain the construction of DC rotating machines.
52. Derive an expression for the emf generated in DC machine.
53. Explain how armature reaction effects to the performance of the machine.
54. Explain the working principle of different types of DC machines and their area of use: separately
exited, self exited (series, shunt and compound).
55. Draw the equivalent circuits of types of DC machines and calculate voltage, current and power
of the machine.
56. Explain the operation of DC machines in two modes: generation and motor.
57. Sketch the performance characteristics of DC machine as generator.
58. Derive expression for torque and speed developed by the motor.
59. Explain the starting methods and sketch speed-torque characteristic of DC motors.
60. Select DC machine for a given application
61. Solve problems related to operation and maintenance of DC machines
62. Explain common faults associated with DC machines
Level 6 Graduate Diploma in Engineering (9210-01) 83