A. between 2 to 4
B. between 6 to 8
C. between 9 to 16
D. between 20 to 30
Related Mcqs:
- In D.C. machines, the ________ in field mmf results in increase in size and cost of machines?
A. increase
B. decrease
C. either of the above
D. none of the above - When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of_____________?
A. short pitch
B. full pitch
C. either of the above
D. none of the above - Electrical machines having power outputs ranging from a few kW up to approximately 250 kW may be classified as_____________?
A. small size machines
B. medium size machines
C. large size machines
D. any of the above - Electrical machines having a power output up to about 750 W may be called__________machines?
A. small size
B. medium size
C. large size
D. any of the above - The design of mechanical parts is particularly important in case of __________ speed machines?
A. low
B. medium
C. high
D. any of the above - Commercial available medium size machines have a speed range of __________ ?
A. 200 to 400 r.p.m
B. 600 to 1000 r.p.m
C. 1000 to 1500 r.p.m
D. 2000 to 2500 r.p.m - _______________is universally used for windings of electrical machines because it is easily workable without any possibility of fracture?
A. Silver
B. Steel
C. Aluminium
D. Copper - Machines cooled by direct cooling method may be called_____________?
A. “supercharged”
B. “inner cooled”
C. “conductor cooled”
D. any of the above - In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made____________?
A. equal to that of armature mmf
B. less in comparison with the armature mmf
C. large in comparison with the armature mmf
D. none of the above - 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
