Q.1
The size of an excavator is usually expressed in terms of
  • "Crowd" motion
  • Angle of swing
  • Cubic meters
  • Travel in meters
Q.2
Ward-Leonard controlled D.C. drives are generally used for _________ excavators.
  • Light duty
  • Medium duty
  • Heavy duty
  • All of the above
Q.3
________ need frequent starting and stopping of electric motors,
  • Paper mills
  • Grinding mills
  • Air-conditioners
  • Lifts and hoists
Q.4
While selecting an electric motor for a floor mill, which electrical characteristics will be of least significance?
  • Running characteristics
  • Starting characteristics
  • Efficiency
  • Braking
Q.5
When the load is above _________ a synchronous motor is found to be more economical.
  • 2 kW
  • 20 kW
  • 50 kW
  • 100 kW
Q.6
Which feature, while selecting a motor for centrifugal pump, will be of least significance?
  • Starting characteristics
  • Operating speed
  • Horse power
  • Speed control
Q.7
In jaw crushers a motor has to often start against ________ load.
  • Heavy
  • Medium
  • Normal
  • Low
Q.8
For which of the following applications D.C. motors are still preferred?
  • High efficiency operation
  • Reversibility
  • Variable speed drive
  • High starting torque
Q.9
The starting torque of a D.C. motor is independent of which of the following?
  • Flux
  • Armature current
  • Flux and armature current
  • Speed
Q.10
In _________ method of staging three phase induction motors the starting voltage is not reduced.
  • Autotransformer
  • Star-delta
  • Slip ring
  • Any of the above
Q.11
Has relatively wider range of speed control.
  • Synchronous motor
  • Ship ring induction motor
  • Squirrel cage induction motor
  • shunt motor
Q.12
For a motor-generator set which of the following motors will be preferred?
  • Synchronous motor
  • Slip ring induction motor
  • Pole changing induction motor
  • Squirrel cage induction motor
Q.13
By the use of which of the following D.C. can be obtained from AC.?
  • Silicon diodes
  • Mercury arc rectifier
  • Motor generator set
  • Any of the above
Q.14
In case of __________ speed control by injecting e.m.f. in the rotor circuit is possible,
  • shunt motor
  • Schrage motor
  • Synchronous motor
  • Slip ring induction motor
Q.15
In ________ the speed can be varied by changing the position of brushes.
  • Slip ring motor
  • Schrage motor
  • Induction motor
  • Repulsion motor
Q.16
Is preferred for automatic drives.
  • Squirrel cage induction motor
  • Synchronous motors
  • Ward Leonard controlled motors
  • Any of the above
Q.17
________ has the least value of starting torque to full load torque ratio.
  • shunt motor
  • series motor
  • Squirrel cage induction motor
  • Slip ring induction motor
Q.18
Rotor of a motor is usually supported on _________ bearings.
  • Ball or roller
  • Needle
  • Bush
  • Thrust
Q.19
A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is
  • Slop speed operation
  • High starting torque
  • Low windage losses
  • All of the above
Q.20
________ has least range of speed control.
  • Slip ring induction motor
  • Synchronous motor
  • shunt motor
  • Schrage motor
Q.21
For a D.C. shunt motor which of the following is incorrect?
  • Unsuitable for heavy duty starting
  • Torque varies as armature current
  • Torque armature current is a straight line
  • Torque is zero for zero armature current
Q.22
Which of the following happens when star-delta starter is used?
  • Starting voltage is reduced
  • Starting current is reduced
  • Both (A) and (B)
  • None of the above
Q.23
__________ method of starting a three phase induction motor needs six terminals.
  • Star-delta
  • Resistance starting
  • Autotransformer
  • None of the above
Q.24
Is preferred for synthetic fibre mills.
  • Synchronous motor
  • Reluctance motor
  • Series motor
  • Shunt motor
Q.25
__________ motor is a constant speed motor.
  • Synchronous motor
  • Schrage motor
  • Induction motor
  • Universal motor
Q.26
For blowers which of the following motor is preferred?
  • series motor
  • shunt motor
  • Squirrel cage induction motor
  • Wound rotor induction motor
Q.27
Which of the following motors is preferred when quick speed reversal is the main consideration?
  • Squirrel cage induction motor
  • Wound rotor induction motor
  • Synchronous motor
  • motor
Q.28
Which of the following motors is preferred for traction work?
  • Universal motor
  • series motor
  • Synchronous motor
  • Three-phase induction motor
Q.29
For derris and winches which of the following drives can be used?
  • Pole changing squirrel cage motors
  • motors with Ward-Leonard control
  • slip ring motors with variable resistance
  • Any of the above
Q.30
In squirrel cage induction motors which of the following methods of starting cannot be used?
  • Resistance in rotor circuit
  • Resistance in stator circuit
  • Autotransformer starting
  • Star-delta starting
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