MCQOPTIONS
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MCQOPTIONS
This section includes 80 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
In a shaded pole motor, the shading coil usually consist of___________? |
| A. | a single turn of heavy wire which is in parallel with running winding |
| B. | a single turn of heavy copper wire which is short-circuited and carries only induced current |
| C. | a multilayer fine gauge copper wire in parallel with running winding |
| D. | none of the above |
| Answer» C. a multilayer fine gauge copper wire in parallel with running winding | |
| 52. |
In a hysteresis motor, the rotor must have____________? |
| A. | retentivity |
| B. | resistivity |
| C. | susceptibility |
| D. | none of the above |
| Answer» B. resistivity | |
| 53. |
In a ceilingfan employing capacitor run motor____________? |
| A. | secondary winding surrounds the primary winding |
| B. | primary winding surrounds the secondary winding |
| C. | both are usual arrangements |
| D. | none of the above |
| Answer» B. primary winding surrounds the secondary winding | |
| 54. |
In a capacitor start motor, the phase displacement between starting and running winding can be nearly__________? |
| A. | 10° |
| B. | 30° |
| C. | 60° |
| D. | 90° |
| Answer» E. | |
| 55. |
In a capacitor start single-phase motor, when capacitor is replaced by a resistance____________? |
| A. | torque will increase |
| B. | the motor will consume less power |
| C. | motor will run in reverse direction |
| D. | motor will continue to run in same direction |
| Answer» E. | |
| 56. |
In a capacitor start and run motors the function of the running capacitor in series with the auxiliary winding is to_______________? |
| A. | improve power factor |
| B. | increase overload capacity |
| C. | reduce fluctuations in torque |
| D. | to improve torque |
| Answer» B. increase overload capacity | |
| 57. |
In a A.C. series motor armature coils are usually connected to commutator____________? |
| A. | through resistance |
| B. | through reactances |
| C. | through capacitors |
| D. | solidly |
| Answer» B. through reactances | |
| 58. |
If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in_________? |
| A. | damage to the starting winding |
| B. | damage to the centrifugal switch |
| C. | overloading of running winding |
| D. | none of the above |
| Answer» B. damage to the centrifugal switch | |
| 59. |
If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then____________? |
| A. | motor will not come up to speed |
| B. | motor will not carry the load |
| C. | current drawn by the motor will be excessively high |
| D. | electrolytic capacitor will, in all probability, suffer break down |
| Answer» E. | |
| 60. |
If the capacitor of a single-phase motor is short-circuited_________? |
| A. | the motor will not start |
| B. | the motor will run |
| C. | the motor will run in reverse direction |
| D. | the motor will run in the same direction at reduced r.p.m |
| Answer» B. the motor will run | |
| 61. |
If starting winding of a single-phase induction motor is left in the circuit, it will____________? |
| A. | run faster |
| B. | spark at light loads |
| C. | draw excessive current and overheat |
| D. | run slower |
| Answer» D. run slower | |
| 62. |
If a single phase induction motor runs slower than normal, the most likely defect is_____________? |
| A. | worn bearings |
| B. | short-circuit in the winding |
| C. | open-circuit in the winding |
| D. | none of the above |
| Answer» B. short-circuit in the winding | |
| 63. |
If a particular application needs high speed and high starting torque, then which of the following motor will be preferred ? |
| A. | Universal motor |
| B. | Shaded pole type motor |
| C. | Capacitor start motor |
| D. | Capacitor start and run motor |
| Answer» B. Shaded pole type motor | |
| 64. |
If a D.C. series motor is operated on A.C. supply, it will____________? |
| A. | spark excessively |
| B. | have poor efficiency |
| C. | have poor power factor |
| D. | all of the above |
| Answer» E. | |
| 65. |
Hysteresis motor is particularly useful for high-quality record players and tape-recorders because___________? |
| A. | it revolves synchronously |
| B. | it is not subject to any magnetic or mechanical vibrations |
| C. | it can be easily manufactured in extremely small sizes of up to 1 W output |
| D. | it develops hysteresis torque which is extremely steady both in amplitude and phase |
| Answer» E. | |
| 66. |
Direction of rotation of a split phase motor can be reversed by reversing the connection of__________? |
| A. | running winding only |
| B. | starting winding only |
| C. | either A. or (b) |
| D. | both A. and (b) |
| Answer» D. both A. and (b) | |
| 67. |
Centrifugal switch disconnects the auxiliary winding of the motor at about ______ percent of synchronous speed? |
| A. | 30 to 40 |
| B. | 70 to 80 |
| C. | 80 to 90 |
| D. | 100 |
| Answer» C. 80 to 90 | |
| 68. |
Burning out of winding is due to___________? |
| A. | short circuited capacitor |
| B. | capacitor value hiving changed |
| C. | open circuiting of capacitor |
| D. | none of the above |
| Answer» B. capacitor value hiving changed | |
| 69. |
As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for__________? |
| A. | fans |
| B. | blowers |
| C. | sound equipment |
| D. | mixer grinders |
| Answer» D. mixer grinders | |
| 70. |
After the starting winding of a single phase induction motor is disconnected from supply, it continues to run only on ______________? |
| A. | running winding |
| B. | rotor winding |
| C. | field winding |
| D. | compensating winding |
| Answer» B. rotor winding | |
| 71. |
A.C. series motor as compared to D.C. series motor has__________? |
| A. | smaller brush width |
| B. | less number of field turns |
| C. | more number of armature turns |
| D. | less air gap |
| E. | all of the above |
| Answer» F. | |
| 72. |
A universal motor can run on___________? |
| A. | A.C. only |
| B. | D.C. only |
| C. | either A.C. or D.C. |
| D. | none of the above |
| Answer» D. none of the above | |
| 73. |
A universal motor is one which______________? |
| A. | can be operated either on D.C. or A.C. supply at approximately the same speed and output |
| B. | can be marketed internationally |
| C. | runs at dangerously high speed on no-load |
| Answer» B. can be marketed internationally | |
| 74. |
A single-phase induction motor is__________? |
| A. | inherently self-starting with high torque |
| B. | inherently self-starting with low torque |
| C. | inherently non-self-starting with low torque |
| D. | inherently non-self-starting with high torque |
| Answer» D. inherently non-self-starting with high torque | |
| 75. |
A shaded pole motor can be used for_____________? |
| A. | toys |
| B. | hair dryers |
| C. | circulators |
| D. | any of the above |
| Answer» E. | |
| 76. |
A shaded pole motor does not possess___________? |
| A. | centrifugal switch |
| B. | capacitor |
| C. | commutator |
| D. | all of the above |
| Answer» E. | |
| 77. |
A schrage motor can run on___________? |
| A. | zero slip |
| B. | negative slip |
| C. | positive slip |
| D. | all of the above |
| Answer» E. | |
| 78. |
A repulsion motor is equipped with__________? |
| A. | slip rings |
| B. | commutator |
| C. | both A. and (b) |
| D. | none of the above |
| Answer» C. both A. and (b) | |
| 79. |
A reluctance motor____________? |
| A. | is self-starting |
| B. | is constant speed motor |
| C. | needs no D.C. excitation |
| D. | all of the above |
| Answer» E. | |
| 80. |
A hysteresis motor works on the principle of__________? |
| A. | hysteresis loss |
| B. | magnetisation of rotor |
| C. | eddy current loss |
| D. | electromagnetic induction |
| Answer» B. magnetisation of rotor | |