MCQOPTIONS
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MCQOPTIONS
This section includes 309 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
_ In a portable instrument, the controlling torque is provided by$? |
| A. | spring |
| B. | gravity |
| C. | eddy currents |
| D. | all of the above |
| Answer» B. gravity | |
| 152. |
_ In order to achieve high accuracy, the slide wire of a potentiometer should be$? |
| A. | as long as possible |
| B. | as short as possible |
| C. | neither too small not too large |
| D. | very thick |
| Answer» B. as short as possible | |
| 153. |
_ For measurement of mutual inductance we can use$? |
| A. | Anderson bridge |
| B. | Maxwell’s bridge |
| C. | Heaviside bridge |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 154. |
_ In majority of instruments damping is provided by$? |
| A. | fluid friction |
| B. | spring |
| C. | eddy currents |
| D. | all of the above |
| Answer» D. all of the above | |
| 155. |
_ Standard resistor is made from$? |
| A. | platinum |
| B. | maganin |
| C. | silver |
| D. | nichrome |
| Answer» C. silver | |
| 156. |
_ The household energy meter is$? |
| A. | an indicating instrument |
| B. | a recording instrument |
| C. | an integrating instrument |
| D. | none of the above |
| Answer» D. none of the above | |
| 157. |
_ Electrical machines having a power output up to about 750 W may be called_______machines.$? |
| A. | small size |
| B. | medium size |
| C. | large size |
| D. | any of the above |
| Answer» B. medium size | |
| 158. |
_ In an Anderson bridge, the unknown inductance is measured in terms of$? |
| A. | known inductance and resistance |
| B. | known capacitance and resistance |
| C. | known resistance |
| D. | known inductance |
| Answer» C. known resistance | |
| 159. |
_ Yokes with rectangular cross-section are used for$? |
| A. | small capacity transformers |
| B. | medium capacity transformers |
| C. | large capacity transformers |
| D. | any of the above |
| Answer» B. medium capacity transformers | |
| 160. |
_ are always double layer type.$? |
| A. | Closed windings |
| B. | Open windings |
| C. | Either of the above |
| D. | None of the above |
| Answer» B. Open windings | |
| 161. |
_ In a D.C. machine the number of brush arms is _____ the number of poles.$? |
| A. | less than |
| B. | equal to |
| C. | greater than |
| D. | none of the above |
| Answer» C. greater than | |
| 162. |
_ Aluminium when adopted as a conductor material in ______ transformers, decreases the overall cost of the transformer$? |
| A. | small size |
| B. | medium size |
| C. | large size |
| D. | any of the above size |
| Answer» B. medium size | |
| 163. |
_ In self cooled motors the cooling time constant is about ______ than the heating time constant because cooling conditions are worse at standstill.$? |
| A. | 2 to 3 times greater |
| B. | 3 to 4 times greater |
| C. | 4 to 5 times greater |
| D. | none of the above |
| Answer» B. 3 to 4 times greater | |
| 164. |
_ D.C. servomotors are used in$? |
| A. | Purely D.C. control systems |
| B. | Purely AC. control systems |
| C. | Both D.C. and AC. control systems |
| D. | None of the above |
| Answer» B. Purely AC. control systems | |
| 165. |
_ In a D.C. machine the current per brush arm should not be more than$? |
| A. | 100 A |
| B. | 200 A |
| C. | 300 A |
| D. | 400 A |
| Answer» E. | |
| 166. |
_Hot rolled sheets have ______ value of permeability$? |
| A. | zero |
| B. | low |
| C. | high |
| D. | none of the above |
| Answer» C. high | |
| 167. |
_The design of mechanical parts is particularly important in case of _____ speed machines.$? |
| A. | low |
| B. | medium |
| C. | high |
| D. | any of the above |
| Answer» D. any of the above | |
| 168. |
________ brushes are fragile and cause excessive wear of commutator,$? |
| A. | Natural graphite |
| B. | Hard carbon |
| C. | Electro graphitic |
| D. | Metal graphite |
| Answer» B. Hard carbon | |
| 169. |
_To measure a resistance with the help of a potentiometer it is$? |
| A. | necessary to standardise the potentiometer |
| B. | not necessary to standardise the potentiometer |
| C. | necessary to use a volt ratio box in conjunction with the potentiometer |
| D. | none of the above |
| Answer» C. necessary to use a volt ratio box in conjunction with the potentiometer | |
| 170. |
_Which of the following is the commonly used type of electromagnets ?$? |
| A. | Flat-faced armature type |
| B. | Horse shoe type |
| C. | Flat-faced plunger type |
| D. | All of the above |
| Answer» E. | |
| 171. |
_In Weston synchronoscope the moving coil is connected across$? |
| A. | bus-bars |
| B. | incoming alternator |
| C. | fixed coils |
| D. | any of the above |
| Answer» B. incoming alternator | |
| 172. |
_The voltage control in electric supply networks in required on account of which of the following reasons ?$? |
| A. | Adjustment of voltage at consumers premises within statutory limits |
| B. | Control of active and reactive power |
| C. | Adjustment of short period daily and seasonal voltage variations in accordance with variations of load |
| D. | All of the above |
| Answer» E. | |
| 173. |
_Volt box is a component to$? |
| A. | extend voltage range |
| B. | measure voltage |
| C. | compare voltage in a box |
| D. | none of the above |
| Answer» B. measure voltage | |
| 174. |
_With direct water cooling it is possible to have ratings of about$? |
| A. | 200 MW |
| B. | 300 MW |
| C. | 400 MW |
| D. | 600 MW |
| Answer» E. | |
| 175. |
_The distance between the starts of two consecutive coils measured in terms of coil sides is called$? |
| A. | front pitch |
| B. | winding pitch |
| C. | commutator pitch |
| D. | back pitch |
| Answer» C. commutator pitch | |
| 176. |
_A moving-coil permanent-magnet instrument can be used as flux meter$? |
| A. | by using a low resistance shunt |
| B. | by using a high series resistance |
| C. | by eliminating the control springs |
| D. | by making control springs of large moment of inertia |
| Answer» D. by making control springs of large moment of inertia | |
| 177. |
In an energy meter braking torque is produced to$? |
| A. | safe guard it against creep |
| B. | brake the instrument |
| C. | bring energy meter to stand still |
| D. | maintain steady speed and equal to driving torque |
| Answer» E. | |
| 178. |
Instrument transformers are$? |
| A. | potential transformers |
| B. | current transformers |
| C. | both (A) and (B) |
| D. | power transformers |
| Answer» D. power transformers | |
| 179. |
In D.C. machines, the ________ in field mmf results in increase in size and cost of machines.$? |
| A. | increase |
| B. | decrease |
| C. | either of the above |
| D. | none of the above |
| Answer» B. decrease | |
| 180. |
In D.C. machines the usual limit of slot pitch is$? |
| A. | between 5 to 10 mm |
| B. | between 10 to 15 mm |
| C. | between 15 to 20 mm |
| D. | between 25 to 35 mm |
| Answer» E. | |
| 181. |
Two holes in the disc of energy meter are drilled at the opposite sides of the spindle to$? |
| A. | improve its ventilation |
| B. | eliminate creeping at no load |
| C. | increase its deflecting torque |
| D. | increase its braking torque |
| Answer» C. increase its deflecting torque | |
| 182. |
Multiple inlet system of air cooling of turbo-alternators can be used for machines of rating upto$? |
| A. | 10 MW |
| B. | 30 MW |
| C. | 60 MW |
| D. | 150 MW |
| Answer» D. 150 MW | |
| 183. |
The pointer of an indicating instrument should be$? |
| A. | very light |
| B. | very heavy |
| C. | either (A) or (B) |
| D. | neither (A) nor (B) |
| Answer» B. very heavy | |
| 184. |
Electrical machines having power outputs ranging from a few kW up to approximately 250 kW may be classified as$? |
| A. | small size machines |
| B. | medium size machines |
| C. | large size machines |
| D. | any of the above |
| Answer» C. large size machines | |
| 185. |
________ is the common method of applying brushes to the commntator.$? |
| A. | Radial |
| B. | Trailing |
| C. | Reaction |
| D. | All of the above |
| Answer» E. | |
| 186. |
Is an instrument which measures the insulation resistance of an electric circuit relative to earth and one another,$? |
| A. | Tangent galvanometer |
| B. | Meggar |
| C. | Current transformer |
| D. | None of the above |
| Answer» C. Current transformer | |
| 187. |
The change in flux linkages can be caused in which of the following ways ?$? |
| A. | The flux is constant with respect to time and is stationary and the coil moves through it |
| B. | The coil is stationary with respect to flux and the flux varies in magnitude with respect to time |
| C. | Both the changes mentioned above occur together, i.e., the coil moves through a time vary-ing field |
| D. | All of the above |
| Answer» E. | |
| 188. |
Which of the following is an essential part of a motor meter ?$? |
| A. | An operating torque system |
| B. | A braking device |
| C. | Revolution registering device |
| D. | All of the above |
| Answer» E. | |
| 189. |
In a single phase power factor meter the phase difference between the currents in the two pressure coils is$? |
| A. | exactly 0° |
| B. | approximately 0° |
| C. | exactly 90° |
| D. | approximately 90° |
| Answer» D. approximately 90¬¨‚àû | |
| 190. |
For measurement of inductance having high value, we should use$? |
| A. | Maxwell’s bridge |
| B. | Maxwell Wein bridge |
| C. | Hay’s bridge |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 191. |
The resistivity of water should not be less than$? |
| A. | 10 Q m |
| B. | 100 Q m |
| C. | 1000 Q m |
| D. | 2000 Q m |
| Answer» E. | |
| 192. |
Wattmeter cannot be designed on the principle of$? |
| A. | electrostatic instrument |
| B. | thermocouple instrument |
| C. | moving iron instrument |
| D. | electrodynamic instrument |
| Answer» D. electrodynamic instrument | |
| 193. |
With conventional hydrogen cooling it is possible to increase the rating of a single unit to$? |
| A. | 50 MW |
| B. | 100 MW |
| C. | 200 MW |
| D. | none of the above |
| Answer» D. none of the above | |
| 194. |
Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?$? |
| A. | Absolute instruments |
| B. | Indicating instruments |
| C. | Recording instruments |
| D. | Integrating instruments |
| Answer» C. Recording instruments | |
| 195. |
Most common form of A.C. meters met with in every day domestic and industrial installations are$? |
| A. | mercury motor meters |
| B. | commutator motor meters |
| C. | induction type single phase energy meters |
| D. | all of the above |
| Answer» D. all of the above | |
| 196. |
The thermal conductivity of hydrogen is ______ times that of air$? |
| A. | 2 |
| B. | 3 |
| C. | 5 |
| D. | 7 |
| Answer» E. | |
| 197. |
The resistance in the circuit of the moving coil of a dynamometer wattmeter should be$? |
| A. | almost zero |
| B. | low |
| C. | high |
| D. | none of the above |
| Answer» D. none of the above | |
| 198. |
The value of exciting or magnetizing current depends upon which of the following factors ?$? |
| A. | Total m.m.f. required |
| B. | The number of turns in the exciting winding |
| C. | The way in which the winding is distributed |
| D. | All of the above |
| Answer» E. | |
| 199. |
The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following?$? |
| A. | Corrugations |
| B. | Fins |
| C. | Tubes |
| D. | All of the above |
| Answer» E. | |
| 200. |
The time taken by the machine to attain 0.632 of its final steady temperature rise is called$? |
| A. | heating time constant |
| B. | cooling time constant |
| C. | either (A) or (B) |
| D. | none of the above |
| Answer» B. cooling time constant | |