1) During plugging, the speed of the motor gradually decreases. If the supply to the motor is not cut - off then the
a. Motor will continue to rotate in the same direction
b. Motor will continue to rotate in the reverse direction
c. Motor will come to rest
d. None of these
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Answer
Explanation
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ANSWER: Motor will come to rest
Explanation:
No explanation is available for this question!
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2) The lighting system of almost all the earlier coaches and all the newly manufactured coaches has
a. 50 V
b. 110 V
c. 220 V
d. 420 V
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Answer
Explanation
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ANSWER: 110 V
Explanation:
No explanation is available for this question!
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3) Pantograph collector is used in railways where the train runs at 100 to 130 kmph. Which among the following is true about pantograph collector?
a. It is unidirectional
b. The erection of the overhead network is complicated
c. Its height cannot be varied
d. None of these
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Answer
Explanation
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ANSWER: None of these
Explanation:
No explanation is available for this question!
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4) A low frequency supply is given to the single phase AC system for track electrification because
a. It improves commutation
b. Increases efficiency
c. Improves power factor
d. All of these
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Answer
Explanation
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ANSWER: All of these
Explanation:
No explanation is available for this question!
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5) For regenerative braking, the motor which is not suitable is
a. DC shunt motor
b. DC compound motor
c. DC deries motor
d. AC shunt motor
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Answer
Explanation
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ANSWER: DC deries motor
Explanation:
No explanation is available for this question!
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6) In case of dc series motor, the torque can be found from
a. Only magnetization curve
b. Only demagnetization curve
c. Both (a) and (b)
d. None of these
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Answer
Explanation
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ANSWER: Only magnetization curve
Explanation:
No explanation is available for this question!
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7) Which among the following is mechanical braking?
a. Pneumatic braking
b. Plugging
c. Dynamic braking
d. Regenerative braking
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Answer
Explanation
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ANSWER: Pneumatic braking
Explanation:
No explanation is available for this question!
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8) Three phase induction motor is not suitable for traction purpose because
a. Low starting torque
b. High starting current
c. Constant speed operation
d. All of these
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Answer
Explanation
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ANSWER: All of these
Explanation:
No explanation is available for this question!
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9) AC series motors are most suitable for
a. Urban services
b. Sub-urban services
c. Main line services
d. All of these
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Answer
Explanation
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ANSWER: Main line services
Explanation:
No explanation is available for this question!
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10) The motor which is most suitable for the traction work is / are
a. DC series motor
b. DC shunt motor
c. Single phase ac series motor
d. Three phase induction motor
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Answer
Explanation
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ANSWER: DC series motor
Explanation:
No explanation is available for this question!
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