MCQOPTIONS
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MCQOPTIONS
This section includes 135 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
__For a particular application the type of electric and control gear are determined by which of the following considerations?__ |
| A. | Starting torque |
| B. | Conditions of environment |
| C. | Limitation on starting current |
| D. | All of the above |
| Answer» E. | |
| 102. |
_In case of __________ speed control by injecting e.m.f. in the rotor circuit is possible,$? |
| A. | D.C. shunt motor |
| B. | Schrage motor |
| C. | Synchronous motor |
| D. | Slip ring induction motor |
| Answer» E. | |
| 103. |
_Is not a part of ball bearing?$? |
| A. | Inner race |
| B. | Outer race |
| C. | Cage |
| D. | Bush |
| Answer» E. | |
| 104. |
_Ward-Leonard controlled D.C. drives are generally used for _________ excavators.$? |
| A. | Light duty |
| B. | Medium duty |
| C. | Heavy duty |
| D. | All of the above |
| Answer» D. All of the above | |
| 105. |
_Which of the following motors is preferred when quick speed reversal is the main consideration?$? |
| A. | Squirrel cage induction motor |
| B. | Wound rotor induction motor |
| C. | Synchronous motor |
| D. | D.C. motor |
| Answer» E. | |
| 106. |
_A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is$? |
| A. | Slop speed operation |
| B. | High starting torque |
| C. | Low windage losses |
| D. | All of the above |
| Answer» C. Low windage losses | |
| 107. |
_In which of the following applications the load on motor changes in cyclic order?$? |
| A. | Electric shovels |
| B. | Cranes |
| C. | Rolling mills |
| D. | All of the above |
| Answer» E. | |
| 108. |
_Flame proof motors are used in$? |
| A. | Paper mills |
| B. | Steel mills |
| C. | Moist atmospheres |
| D. | Explosive atmospheres |
| Answer» E. | |
| 109. |
_For derris and winches which of the following drives can be used?$? |
| A. | Pole changing squirrel cage motors |
| B. | D.C. motors with Ward-Leonard control |
| C. | A.C. slip ring motors with variable resistance |
| D. | Any of the above |
| Answer» E. | |
| 110. |
In _________ method of staging three phase induction motors the starting voltage is not reduced.$? |
| A. | Autotransformer |
| B. | Star-delta |
| C. | Slip ring |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 111. |
In which of the following applications variable speed operation is preferred?$? |
| A. | Exhaust fan |
| B. | Ceiling fan |
| C. | Refrigerator |
| D. | Water pump |
| Answer» C. Refrigerator | |
| 112. |
Besides a constant speed a synchronous rotor possesses which of the following advantages?$? |
| A. | Lower cost |
| B. | Better efficiency |
| C. | High power factor |
| D. | All of the above |
| Answer» D. All of the above | |
| 113. |
Which of the following happens when star-delta starter is used?$? |
| A. | Starting voltage is reduced |
| B. | Starting current is reduced |
| C. | Both (A) and (B) |
| D. | None of the above |
| Answer» D. None of the above | |
| 114. |
Which of the following motors always starts on load?$? |
| A. | Conveyor motor |
| B. | Floor mill motor |
| C. | Fan motor |
| D. | All of the above |
| Answer» E. | |
| 115. |
The diameter of the rotor shaft for an electric motor depends on which of the following? |
| A. | r.p.m. only |
| B. | Horse power only |
| C. | Horse power and r.p.m. |
| D. | Horse power, r.p.m. and power factor |
| Answer» D. Horse power, r.p.m. and power factor | |
| 116. |
For which of the following applications D.C. motors are still preferred? |
| A. | High efficiency operation |
| B. | Reversibility |
| C. | Variable speed drive |
| D. | High starting torque |
| Answer» D. High starting torque | |
| 117. |
Which of the following motors is used for elevators? |
| A. | Induction motor |
| B. | Synchronous motor |
| C. | Capacitor start single phase motor |
| D. | Any of the above |
| Answer» B. Synchronous motor | |
| 118. |
While selecting an electric motor for a floor mill, which electrical characteristics will be of least significance? |
| A. | Running characteristics |
| B. | Starting characteristics |
| C. | Efficiency |
| D. | Braking |
| Answer» E. | |
| 119. |
Which part of a motor needs maximum attention for maintenance? |
| A. | Frame |
| B. | Rearing |
| C. | Stator winding |
| D. | Rotor winding |
| Answer» C. Stator winding | |
| 120. |
________ has least range of speed control. |
| A. | Slip ring induction motor |
| B. | Synchronous motor |
| C. | D.C. shunt motor |
| D. | Schrage motor |
| Answer» C. D.C. shunt motor | |
| 121. |
The traveling speed of cranes varies from |
| A. | 20 to 30 m/s |
| B. | 10 to 15 m/s |
| C. | 5 to 10 m/s |
| D. | 1 to 2.5 m/s |
| Answer» E. | |
| 122. |
When the load is above _________ a synchronous motor is found to be more economical. |
| A. | 2 kW |
| B. | 20 kW |
| C. | 50 kW |
| D. | 100 kW |
| Answer» E. | |
| 123. |
Heat control switches are used in |
| A. | Transformers |
| B. | Cooling ranges |
| C. | Three phase induction motors |
| D. | Single phase |
| Answer» C. Three phase induction motors | |
| 124. |
Which of the following motors are best for the rolling mills? |
| A. | Single phase motors |
| B. | Squirrel cage induction motors |
| C. | Slip ring induction motors |
| D. | D.C. motors |
| Answer» E. | |
| 125. |
While selecting motor for an air conditioner which of the following characteristics is of great importance? |
| A. | Type of bearings |
| B. | Type of enclosure |
| C. | Noise |
| D. | Arrangement for power transmission |
| Answer» D. Arrangement for power transmission | |
| 126. |
For a D.C. shunt motor which of the following is incorrect? |
| A. | Unsuitable for heavy duty starting |
| B. | Torque varies as armature current |
| C. | Torque armature current is a straight line |
| D. | Torque is zero for zero armature current |
| Answer» B. Torque varies as armature current | |
| 127. |
Which of the following alternatives will be cheaper? |
| A. | A 100 H.P. AC. three phase motor |
| B. | Four motors of 25 H.P. each |
| C. | Five motors of 20 H.P. each |
| D. | Ten motors of 10 H.P. each |
| Answer» B. Four motors of 25 H.P. each | |
| 128. |
Light duty cranes are used in which of the following? |
| A. | Power houses |
| B. | Pumping stations |
| C. | Automobile workshops |
| D. | All of the above |
| Answer» E. | |
| 129. |
In jaw crushers a motor has to often start against ________ load. |
| A. | Heavy |
| B. | Medium |
| C. | Normal |
| D. | Low |
| Answer» B. Medium | |
| 130. |
The load cycle for a motor driving a power press will be |
| A. | Variable load |
| B. | Continuous |
| C. | Continuous but periodical |
| D. | Intermittent and variable load |
| Answer» E. | |
| 131. |
Which feature, while selecting a motor for centrifugal pump, will be of least significance? |
| A. | Starting characteristics |
| B. | Operating speed |
| C. | Horse power |
| D. | Speed control |
| Answer» E. | |
| 132. |
Which of the following motors has series characteristics? |
| A. | Shaded pole motor |
| B. | Repulsion motor |
| C. | Capacitor start motor |
| D. | None of the above |
| Answer» C. Capacitor start motor | |
| 133. |
Has relatively wider range of speed control. |
| A. | Synchronous motor |
| B. | Ship ring induction motor |
| C. | Squirrel cage induction motor |
| D. | D.C. shunt motor |
| Answer» E. | |
| 134. |
Which of the following motors is preferred for boom hoist of a traveling crane? |
| A. | Single phase motor |
| B. | Synchronous motor |
| C. | A.C. slip ring motor |
| D. | Ward-Leonard controlled D.C. shunt motor |
| Answer» D. Ward-Leonard controlled D.C. shunt motor | |
| 135. |
Rotor of a motor is usually supported on _________ bearings. |
| A. | Ball or roller |
| B. | Needle |
| C. | Bush |
| D. | Thrust |
| Answer» B. Needle | |