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.
| 251. |
The insulation between windings and grounded core and the insulation between the windings of the same phase is |
| A. | minor insulation |
| B. | major insulation |
| C. | either of the above |
| D. | none of the above |
| Answer» B. major insulation | |
| 252. |
The surge phenomenon is particularly important in case of |
| A. | low voltage transformers |
| B. | medium voltage transformers |
| C. | high voltage transformers |
| D. | any of the above |
| Answer» D. any of the above | |
| 253. |
Is universally used for windings of electrical machines because it is easily workable without any possibility of |
| A. | fracture |
| B. | Silver |
| C. | Steel |
| D. | Aluminium |
| E. | Copper |
| Answer» E. Copper | |
| 254. |
In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made |
| A. | equal to that of armature mmf |
| B. | less in comparison with the armature mmf |
| C. | large in comparison with the armature mmf |
| D. | none of the above |
| Answer» D. none of the above | |
| 255. |
The cold rolled grain oriented steel has ______ permeability in the direction of the grain orientation. |
| A. | minimum |
| B. | maximum |
| C. | nil |
| D. | none of the above |
| Answer» C. nil | |
| 256. |
The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a |
| A. | single-phase winding |
| B. | two-phase winding |
| C. | three-phase winding |
| D. | any of the above |
| Answer» C. three-phase winding | |
| 257. |
Which of the following is an advantage of hydrogen cooling? |
| A. | Increase in efficiency |
| B. | Increase in ratings |
| C. | Increase in life |
| D. | All of the above |
| Answer» E. | |
| 258. |
Impose limitation on design. |
| A. | Saturation |
| B. | Temperature rise |
| C. | Efficiency |
| D. | Power factor |
| E. | All above |
| Answer» F. | |
| 259. |
Commonly used instruments in power system measurement are |
| A. | induction |
| B. | moving coil or iron |
| C. | rectifier |
| D. | electrostatic |
| Answer» B. moving coil or iron | |
| 260. |
The electrical power to a meggar is provided by |
| A. | battery |
| B. | permanent magnet D.C. generator |
| C. | A.C. generator |
| D. | any of the above |
| Answer» C. A.C. generator | |
| 261. |
To measure radio frequency, the suitable frequency meter is |
| A. | Weston frequency meter |
| B. | reed vibrator frequency meter |
| C. | heterodoxy frequency meter |
| D. | electrical resonance frequency meter |
| Answer» D. electrical resonance frequency meter | |
| 262. |
Which of the following is the major consideration to evolve a good design ? |
| A. | Cost |
| B. | Durability |
| C. | Compliance with performance criteria as laid down in specifications |
| D. | All of the above |
| Answer» E. | |
| 263. |
Which of the following brushes can be used for high values of current density ? |
| A. | Metal graphite brushes |
| B. | Hard carbon brushes |
| C. | Electro-graphitic brushes |
| D. | Natural graphite brushes |
| Answer» B. Hard carbon brushes | |
| 264. |
Multilayer helical windings are commonly used in the transformers as high voltage windings |
| A. | upto 20 kV |
| B. | upto 50 kV |
| C. | upto 80 kV |
| D. | for 110 kV and above |
| Answer» E. | |
| 265. |
The usual values of maximum flux densities for distribution transformers using hot rolled silicon steel are |
| A. | 0.5 to 0.8 Wb/m² |
| B. | 0.8 to 1.0 Wb/m² |
| C. | 1.1 to 1.35 Wb/m² |
| D. | 1.4 to 1.8 Wb/m² |
| Answer» D. 1.4 to 1.8 Wb/m¬¨‚⧠| |
| 266. |
Induction type single phase energy meters measure electric energy in |
| A. | kW |
| B. | Wh |
| C. | kWh |
| D. | VAR |
| E. | None of the above |
| Answer» D. VAR | |
| 267. |
The principle on which vector voltmeter is based is |
| A. | that it works on the principle of complex variation |
| B. | that it measures the response of linear ramp voltage |
| C. | same as digital meter |
| D. | that it measures the amplitude of a single at two points and at the same time measures their phase difference |
| Answer» E. | |
| 268. |
The operating voltage of a meggar is about |
| A. | 6 V |
| B. | 12 V |
| C. | 40 V |
| D. | 100 V |
| Answer» E. | |
| 269. |
Which of the following essential features is possessed by an indicating instrument ? |
| A. | Deflecting device |
| B. | Controlling device |
| C. | Damping device |
| D. | All of the above |
| Answer» E. | |
| 270. |
Which of the following is the basic consideration in the design of insulation ? |
| A. | Electrical considerations |
| B. | Mechanical considerations |
| C. | Thermal considerations |
| D. | All of the above |
| Answer» E. | |
| 271. |
Commercial available medium size machines have a speed range of ______ . |
| A. | 200 to 400 r.p.m. |
| B. | 600 to 1000 r.p.m. |
| C. | 1000 to 1500 r.p.m. |
| D. | 2000 to 2500 r.p.m. |
| Answer» E. | |
| 272. |
In a Schering bridge the potential of the detector above earth potential is |
| A. | a few volts only |
| B. | 1 kV |
| C. | 5 kV |
| D. | 10 kV |
| Answer» B. 1 kV | |
| 273. |
Operating torques in analogue instruments are |
| A. | deflecting and control |
| B. | deflecting and damping |
| C. | deflecting, control and damping |
| D. | vibration and balancing |
| Answer» D. vibration and balancing | |
| 274. |
Which of the following devices may be used for extending the range of instruments ? |
| A. | Shunts |
| B. | Multipliers |
| C. | Current transformers |
| D. | Potential transformers |
| E. | All of the above |
| Answer» F. | |
| 275. |
Dummy coil should not be used in |
| A. | small machines |
| B. | large machines |
| C. | either (A) or (B) |
| D. | none of the above |
| Answer» C. either (A) or (B) | |
| 276. |
Power transformers have rating |
| A. | equal to 50 kVA |
| B. | equal to 100 kVA |
| C. | above 200 kVA |
| D. | none of the above |
| Answer» D. none of the above | |
| 277. |
________ cooling is the process of dissipating the armature and field winding losses to a cooling medium circulating within the winding insulation wall |
| A. | Direct |
| B. | Indirect |
| C. | Conventional |
| D. | Any of the above |
| Answer» B. Indirect | |
| 278. |
On which of the following variables heat convected depends ? |
| A. | Power density |
| B. | Temperature difference between heated surface and coolant |
| C. | Thermal resistivity, density, specific heat |
| D. | Gravitational constant |
| E. | All of the above |
| Answer» F. | |
| 279. |
Which of the following methods may be adopted to reduce the effects of armature reaction? |
| A. | Increase in length of air gap at pole tips |
| B. | Increasing reluctance of pole tips |
| C. | Compensating windings |
| D. | All of the above |
| Answer» E. | |
| 280. |
An induction meter can handle current up to |
| A. | 10 A |
| B. | 30 A |
| C. | 60 A |
| D. | 100 A |
| Answer» E. | |
| 281. |
In a low power factor wattmeter the pressure coil is connected |
| A. | to the supply side of the current coil |
| B. | to the load side of the current coil |
| C. | in any of the two meters at connection |
| D. | none of the above |
| Answer» C. in any of the two meters at connection | |
| 282. |
A sensitive galvanometer produces large deflection for a |
| A. | small value of current |
| B. | large value of current |
| C. | large value of power |
| D. | large value of voltage |
| E. | none of the above |
| Answer» B. large value of current | |
| 283. |
According to application, instruments are classified as |
| A. | switch board |
| B. | portable |
| C. | both (A) and (B) |
| D. | moving coil |
| E. | moving iron |
| Answer» D. moving coil | |
| 284. |
For 275 kV transformers, using cold rolled grain oriented steel, which of the following values of flux density may be used? |
| A. | 1.0 Wb/m² |
| B. | 1.1 Wb/m² |
| C. | 1.3 Wb/m² |
| D. | 1.6 Wb/m² |
| E. | None of the above |
| Answer» E. None of the above | |
| 285. |
In direct cooled system using hydrogen both stator and rotor conductors are made |
| A. | solid |
| B. | hollow |
| C. | perforated |
| D. | any ofthe above |
| Answer» C. perforated | |
| 286. |
When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of |
| A. | short pitch |
| B. | full pitch |
| C. | either of the above |
| D. | none of the above |
| Answer» C. either of the above | |
| 287. |
In transformers using hot rolled steel, the cross-section of the yoke is made about _____ greater than that of the core |
| A. | 5 percent |
| B. | 10 percent |
| C. | 15 percent |
| D. | 30 percent |
| E. | none of the above |
| Answer» D. 30 percent | |
| 288. |
The use of _____ instruments is merely confined within laboratories as standardizing instruments. |
| A. | absolute |
| B. | indicating |
| C. | recording |
| D. | integrating |
| E. | none of the above |
| Answer» B. indicating | |
| 289. |
If an inductance is connected in one arm of bridge and resistances in the remaining three arms |
| A. | the bridge can always be balanced |
| B. | the bridge cannot be balanced |
| C. | the bridge can be balanced if the resistances have some specific values |
| D. | none of the above |
| Answer» C. the bridge can be balanced if the resistances have some specific values | |
| 290. |
Direct water cooling of rotor winding presents |
| A. | No mechanical difficulties |
| B. | Lesser mechanical difficulties |
| C. | Greater mechanical difficulties |
| D. | None of the above |
| Answer» D. None of the above | |
| 291. |
The disc of an instrument using eddy current damping should be of |
| A. | conducting and magnetic material |
| B. | non-conducting and magnetic material |
| C. | conducting and non-magnetic material |
| D. | none of the above |
| Answer» D. none of the above | |
| 292. |
By which of the following methods motor rating for variable load drives can be determined ? |
| A. | Method of average losses |
| B. | Equivalent current method |
| C. | Equivalent torque method |
| D. | Equivalent power method |
| E. | All of the above |
| Answer» F. | |
| 293. |
A potentiometer may be used for |
| A. | measurement of resistance |
| B. | measurement of current |
| C. | calibration of ammeter |
| D. | calibration of voltmeter |
| E. | all of the above |
| Answer» F. | |
| 294. |
Which of the following properties a damping oil must possess ? |
| A. | Must be a good insulator |
| B. | Should be non-evaporating |
| C. | Should not have corrosive action upon the metal of the vane |
| D. | The viscosity of the oil should not change with the temperature |
| E. | All of the above |
| Answer» F. | |
| 295. |
Which of the following are integrating instruments ? |
| A. | Ammeters |
| B. | Voltmeters |
| C. | Wattmeters |
| D. | Ampere-hour and watt-hour meters |
| Answer» E. | |
| 296. |
Resistances can be measured with the help of |
| A. | wattmeters |
| B. | voltmeters |
| C. | ammeters |
| D. | ohmmeters and resistance bridges |
| E. | all of the above |
| Answer» E. all of the above | |
| 297. |
Most sensitive galvanometer is |
| A. | elastic galvanometer |
| B. | vibration galvanometer |
| C. | Duddlb galvanometer |
| D. | spot ballistic galvanometer |
| Answer» E. | |
| 298. |
The design of electromagnets is based upon which of the following fundamental equations ? |
| A. | Force equation |
| B. | Magnetic circuit equation |
| C. | Heating equation |
| D. | Voltage equation |
| E. | All of the above |
| Answer» F. | |
| 299. |
_________ electromagnets generally function as holding magnets. |
| A. | Tractive |
| B. | Portative |
| C. | Either of the above |
| D. | None of the above |
| Answer» C. Either of the above | |
| 300. |
The action of electromagnetic machines can be related to which of the following basic principles ? |
| A. | Induction |
| B. | Interaction |
| C. | Alignment |
| D. | All of the above |
| Answer» E. | |