113. Regenerative breaking in shunt motors is used when
A. the load is variable
B. the load is constantly decreasing
C. the load has overhauling characteristics
D. the load also acts as a braking force

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114. The most economical method of electrical braking of a dc motor is
A. regenerative braking
B. dynamic braking with self excitation
C. dynamic braking with separate excitation
D. plugging

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115. For nonreversing dc drives, it is preferred to employ
A. regenerative braking
B. dynamic braking with separate excitation
C. dynamic braking with self excitation
D. plugging

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116. Which of the following dc motor is used for intermittent high torque load
A. dc series motors
B. dc shunt motor
C. differential compound motor
D. cumulative compound motor

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117. DC series motor are best suited for traction because
A. torque is proportional to the square of the armature current and speed is proportional to the torque
B. torque is proportional to square of the armature current and speed is inversely proportional to the torque
C. torque and speed both are proportional to the square of the armature current
D. none of these

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118. Which dc motor should not be used for centrifugal pumps?
A. shnt motor
B. series motor
C. cumulatively compound motor
D. differentially compound motor

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119. Which of the following test is most economical in finding the no load losses of a large dc shunt motor?
A. Swinburne test
B. Hopkinson test
C. retardation test
D. none of these

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