A. quiet
B. noisy
C. either of the above
D. none of the above
Related Mcqs:
- D.C. machines designed with a large value of air gap length have_____________?
A. worst, ventilation
B. poor ventilation
C. better ventilation
D. none of the above - In induction motors, the length of air gap in kept as small as mechanically possible is order to have____________?
A. low power factor
B. high power factor
C. high over load capacity
D. any of the above - The length cf air gap to be provided in __________ is primarily determined by power factor consideration?
A. d.c. series motor .
B. d.c. shunt motor
C. induction motor
D. synchronous motor - For large power transformers, self oil cooled type or air blast type which of the following values of current density may be used?
A. 1.0 to 1.2 A/mm2
B. 1.5 to 2.0 A/mm2
C. 2.2 to 3.2 A/mm2
D. 3.2 to 4.2 A/mm2 - The efficiency of a machine should be as ____________ as possible to reduce the operating cost?
A. high
B. low
C. either of the above
D. none of the above - The time taken by the machine to attain 0.632 of its final steady temperature rise is called_____________?
A. heating time constant
B. cooling time constant
C. either A. or B.
D. none of the above - In a D.C. machine the current per brush arm should not be more than_____________?
A. 100 A
B. 200 A
E. 300 A
D. 400 A - In a D.C. machine, the value of peripheral speed should not, normally, exceed___________?
A. 10 m/s
B. 20 m/s
C. 30 m/s
D. 40 m/s - In a D.C. machine the number of brush arms is _________ the number of poles?
A. less than
B. equal to
C. greater than
D. none of the above - The laminations of the armature of a D.C. machine are usually ___________ thick?
A. 0.1 to 0.2 mm
B. 0.2 to 0.3 mm
C. 0.3 to 0.4 mm
D. 0.4 to 0.5 mm
