ONLINE Multiple Choice Questions – Electric Machine Design PART 4


46. An ideal liquid insulating material should have low
(A) heat conductivity
(B) dielectric strength
(C) mechanical strength
(D) volatility.

Get Answer

47. The electric breakdown strength of an instating material depends on
(A) composition of the material
(B) thickness of the material
(C) time of application of voltage
(D) all of the above.

Get Answer

48. When V is the voltage applied across the insulation, the dielectric loss for an insulating material will be proportional to
(A) V
(B) V2
(C) 1/ V
(D) 1/ V2

Get Answer

49. When δ is the dielectric loss angle, the value of tan δ increases with
(A) decrease in temperature
(B) presence of moisture
(C) voltage
(D) all of the above.

Get Answer

50. Which has lowest dielectric strength
(A) Cotton
(B) Empire cloth
(C) Porcelain
(D) Mica.

Get Answer

51. Silicon steel E330 indicates that
(A) it has 33% silicon
(B) it has normal specific loss at 50 Hz
(C) it is cold rolled grain oriented
(D) all of the above.

Get Answer

52. Which of the following silicon steel will have least specific lose ?
(A) E11
(B) E42
(C) E31
(D) E41

Get Answer

54. In silicon steel designation like E320 the first figure 3 indicates
(A) the percentage of silicon
(B) the specific loss at 50 Hz
(C) the specific lose at 100 Hz
(D) the grain oriented cold rolled variety.

Get Answer

55. In silicon steel designation like E320 , the second figure 2 represent
(A) specific loss
(B) direction of grain orientation
(C) magnetic variety
(D) non-magnetic variety.

Get Answer

56. In high nickel alloys the percentage of nickel is
(A) 5 to 10 percent
(B) 10 to 20 percent
(C) 30 to 50 percent
(D) 70 to 80 percent.

Get Answer

57. Pumps, blowers and fans are usually called for
(A) continuous duty
(B) short time duty
(C) intermittent periodic duty
(D) intermittent periodic duty with starting and braking.

Get Answer

58. Which of the following is normally called for continuous duty with starting and braking ?
(A) Machine tools
(B) Compressors
(C) Sirens
(D) Escalators.

Get Answer

59. In lap windings, the equalizer rings arc used to save
(A) armature winding from carrying circulating currents
(B) commutator from carrying circulating currents
(C) brushes from carrying circulating currents
(D) armature core from eddy currents.

Get Answer

60. Which of the following calls for intermittent duty with starting and braking ?
(A) Pumps
(B) Conveyors
(C) Wind lasses
(D) Cranes.

Get Answer

ONLINE Multiple Choice Questions - Electric Machine Design PART 5
ONLINE Multiple Choice Questions - Electric Machine Design PART 3

Leave a Reply