A. small capacity transformers
B. medium capacity transformers
C. large capacity transformers
D. any of the above
Related Mcqs:
- In transformers using hot rolled steel, the cross-section of the yoke is made about __________ greater than that of the core?
A. 5 percent
B. 10 percent
C. 15 percent
D. 30 percent
E. 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 - __________ has a low relative permeability and is used principally in field frames when cost is of primary importance and extra weight is not objectionable?
A. Cast steel
B. Aluminium
C. Soft steel
D. Cast iron - __________is extensively used for those portions of magnetic circuit which carry steady flux and need superior mechanical properties ?
A. Grey cast-iron
B. Cast steel
C. High carbon steel
D. Stainless steel - Machines cooled by direct cooling method may be called_____________?
A. “supercharged”
B. “inner cooled”
C. “conductor cooled”
D. any of the above - The design of electromagnets is based upon which of the following fundamental equations ?
A. Force equation
B. Magnetic circuit equation
C. Heating equation
D. Voltage equation
E. All of the above - Dummy coil should not be used in_________________?
A. small machines
B. large machines
C. either A. or B.
D. none of the above - 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 - A practical formula for determining the thickness of insulation between low voltage and high voltage windings is__________________?
A. 1 + 0.2 kVmm
B. 2 + 0.5 kVmm
C. 4 + 0.7 kV mm
D. 5 + 0.9 kV mm - Multi-layer helical windings are commonly used in the transformers as high voltage windings_______________?
A. upto 20 kV
B. upto 50 kV
C. upto 80 kV
D. for 110 kV and above
