260. D.C. generators are installed near the load centres to reduce
A. iron losses
B. line losses
C. sparking
D. corona losses
261. The purpose of retardation test on D.C. shunt machines is to find out
A. stray losses
B. eddy current losses
C. field copper losse
D. windage losse
262. Which of the following tests will be suitable for testing two similar D.C. series motors of large capacity?
A. Swinburne's test
B. Hopkinson's test
C. Field test
D. Brake test
263. Hopkinson's test on D.C. machines is conducted at
A. no-load
B. part load
C. full-load
D. overload
264. During Rheostat braking of D.C. series motors
A. motor is run as a generator
B. motor is reversed in direction
C. motor is run at reduced speed
D. motor runs in toggle mode
265. For which types of D.C. motor, dynamic braking is generally used?
A. Shunt motors
B. Series motors
C. Compound motors
D. All of the above
266. During rheostatic braking the braking torque is proportional to
A. speed
B. (speed)2
C. (speedri
D. (speed)-2
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