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.
| 1. |
The operation of a D.C. machine with large air gap lengths is comparatively |
| A. | uiet |
| B. | oisy |
| C. | ither of the above |
| D. | one of the above |
| Answer» B. oisy | |
| 2. |
In a D.C. machine the number of brush arms is _____ the number of poles. |
| A. | ess than |
| B. | qual to |
| C. | reater than |
| D. | one of the above |
| Answer» C. reater than | |
| 3. |
The change in flux linkages can be caused in which of the following ways ? |
| A. | he flux is constant with respect to time and is stationary and the coil moves through it |
| B. | he coil is stationary with respect to flux and the flux varies in magnitude with respect to time |
| C. | oth the changes mentioned above occur together, i.e., the coil moves through a time vary-ing field |
| D. | ll of the above |
| Answer» E. | |
| 4. |
Yokes with rectangular cross-section are used for |
| A. | mall capacity transformers |
| B. | edium capacity transformers |
| C. | arge capacity transformers |
| D. | ny of the above |
| Answer» B. edium capacity transformers | |
| 5. |
________ is the common method of applying brushes to the commntator. |
| A. | adial |
| B. | railing |
| C. | eaction |
| D. | ll of the above |
| Answer» E. | |
| 6. |
Commonly used standard capacitor is |
| A. | pherical type |
| B. | oncentric cylindrical type |
| C. | lectrostatic type |
| D. | ultilayer parallel plate type |
| Answer» C. lectrostatic type | |
| 7. |
Aluminium when adopted as a conductor material in ______ transformers, decreases the overall cost of the transformer |
| A. | mall size |
| B. | edium size |
| C. | arge size |
| D. | ny of the above size |
| Answer» B. edium size | |
| 8. |
The mcrease in heat dissipation by air blasts is due to increase in |
| A. | onduction |
| B. | onvection |
| C. | adiation |
| D. | ny ofthe above |
| Answer» C. adiation | |
| 9. |
are always double layer type. |
| A. | losed windings |
| B. | pen windings |
| C. | ither of the above |
| D. | one of the above |
| Answer» B. pen windings | |
| 10. |
The power of a n-phase circuit can be measured by using a minimum of |
| A. | n – 1) wattmeter elements |
| B. | wattmeter elements |
| C. | n + 1) wattmeter elements |
| D. | n wattmeter elements |
| Answer» B. wattmeter elements | |
| 11. |
In self cooled motors the cooling time constant is about ______ than the heating time constant because cooling conditions are worse at standstill. |
| A. | to 3 times greater |
| B. | to 4 times greater |
| C. | to 5 times greater |
| D. | one of the above |
| Answer» B. to 4 times greater | |
| 12. |
In a single phase power factor meter the phase difference between the currents in the two pressure coils is |
| A. | xactly 0° |
| B. | pproximately 0° |
| C. | xactly 90° |
| D. | pproximately 90° |
| Answer» D. pproximately 90° | |
| 13. |
Systematic errors are |
| A. | nstrumental errors |
| B. | nvironmental errors |
| C. | bservational errors |
| D. | ll of the above |
| Answer» E. | |
| 14. |
D.C. servomotors are used in |
| A. | urely D.C. control systems |
| B. | urely AC. control systems |
| C. | oth D.C. and AC. control systems |
| D. | one of the above |
| Answer» B. urely AC. control systems | |
| 15. |
For measurement of inductance having high value, we should use |
| A. | axwell’s bridge |
| B. | axwell Wein bridge |
| C. | ay’s bridge |
| D. | ny of the above |
| Answer» D. ny of the above | |
| 16. |
In an AC co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be |
| A. | ut of phase by 90° |
| B. | ut of phase by 60° |
| C. | ut of phase by 30° |
| D. | ut of phase by 0° |
| Answer» B. ut of phase by 60° | |
| 17. |
For measuring current at high frequency we should use |
| A. | oving iron instrument |
| B. | lectrostatic instrument |
| C. | hermocouple instrument |
| D. | one of the above |
| Answer» D. one of the above | |
| 18. |
Volt box is a component to |
| A. | xtend voltage range |
| B. | easure voltage |
| C. | ompare voltage in a box |
| D. | one of the above |
| Answer» B. easure voltage | |
| 19. |
The power factor of a single phase load can be calculated if the instruments available are |
| A. | ne voltmeter and one ammeter |
| B. | ne voltmeter, one ammeter and one wattmeter |
| C. | ne voltmeter, one ammeter and one energy meter |
| D. | ny of the above |
| Answer» C. ne voltmeter, one ammeter and one energy meter | |
| 20. |
In a D.C. machine the current per brush arm should not be more than |
| A. | 00 A |
| B. | 00 A |
| C. | 00 A |
| D. | 00 A |
| Answer» E. | |
| 21. |
The resistivity of water should not be less than |
| A. | 0 Q m |
| B. | 00 Q m |
| C. | 000 Q m |
| D. | 000 Q m |
| Answer» E. | |
| 22. |
The desirable static characteristics of a measuring system are |
| A. | ccuracy and reproducibility |
| B. | ccuracy, sensitivity and reproducibility |
| C. | rift and dead zone |
| D. | tatic error |
| Answer» C. rift and dead zone | |
| 23. |
Electrical machines having power outputs ranging from a few kW up to approximately 250 kW may be classified as |
| A. | mall size machines |
| B. | edium size machines |
| C. | arge size machines |
| D. | ny of the above |
| Answer» C. arge size machines | |
| 24. |
The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc. |
| A. | onduction |
| B. | onvection |
| C. | adiation |
| D. | ny of the above |
| Answer» D. ny of the above | |
| 25. |
Electrical machines having a power output up to about 750 W may be called_______machines. |
| A. | mall size |
| B. | edium size |
| C. | arge size |
| D. | ny of the above |
| Answer» B. edium size | |
| 26. |
The flash point of transformer oil should be higher than |
| A. | 0°C |
| B. | 0°C |
| C. | 0°C |
| D. | 04°C |
| Answer» E. | |
| 27. |
Multiple inlet system of air cooling of turbo-alternators can be used for machines of rating upto |
| A. | 0 MW |
| B. | 0 MW |
| C. | 0 MW |
| D. | 50 MW |
| Answer» D. 50 MW | |
| 28. |
Standard resistor is made from |
| A. | latinum |
| B. | aganin |
| C. | ilver |
| D. | ichrome |
| Answer» C. ilver | |
| 29. |
Two holes in the disc of energy meter are drilled at the opposite sides of the spindle to |
| A. | mprove its ventilation |
| B. | liminate creeping at no load |
| C. | ncrease its deflecting torque |
| D. | ncrease its braking torque |
| Answer» C. ncrease its deflecting torque | |
| 30. |
In D.C. machines the number of slots per pole usually lies |
| A. | etween 2 to 4 |
| B. | etween 6 to 8 |
| C. | etween 9 to 16 |
| D. | etween 20 to 30 |
| Answer» D. etween 20 to 30 | |
| 31. |
In order to achieve high accuracy, the slide wire of a potentiometer should be |
| A. | s long as possible |
| B. | s short as possible |
| C. | either too small not too large |
| D. | ery thick |
| Answer» B. s short as possible | |
| 32. |
Instrument transformers are |
| A. | otential transformers |
| B. | urrent transformers |
| C. | oth (A) and (B) |
| D. | ower transformers |
| Answer» D. ower transformers | |
| 33. |
In a meggar controlling torque is provided by |
| A. | pring |
| B. | ravity |
| C. | oil |
| D. | ddy current |
| Answer» D. ddy current | |
| 34. |
In a portable instrument, the controlling torque is provided by |
| A. | pring |
| B. | ravity |
| C. | ddy currents |
| D. | ll of the above |
| Answer» B. ravity | |
| 35. |
In an energy meter braking torque is produced to |
| A. | afe guard it against creep |
| B. | rake the instrument |
| C. | ring energy meter to stand still |
| D. | aintain steady speed and equal to driving torque |
| Answer» E. | |
| 36. |
In a low power factor wattmeter the compensating coil is connected |
| A. | n series with current coil |
| B. | n parallel with current coil |
| C. | n series with pressure coil |
| D. | n parallel with pressure coil |
| Answer» D. n parallel with pressure coil | |
| 37. |
For measurement of mutual inductance we can use |
| A. | nderson bridge |
| B. | axwell’s bridge |
| C. | eaviside bridge |
| D. | ny of the above |
| Answer» D. ny of the above | |
| 38. |
In D.C. machines, the ________ in field mmf results in increase in size and cost of machines. |
| A. | ncrease |
| B. | ecrease |
| C. | ither of the above |
| D. | one of the above |
| Answer» B. ecrease | |
| 39. |
_______ instruments are those which measure the total quantity of electricity delivered in a particular time. |
| A. | bsolute |
| B. | ndicating |
| C. | ecording |
| D. | ntegrating |
| Answer» E. | |
| 40. |
In majority of instruments damping is provided by |
| A. | luid friction |
| B. | pring |
| C. | ddy currents |
| D. | ll of the above |
| Answer» D. ll of the above | |
| 41. |
In D.C. machines the usual limit of slot pitch is |
| A. | etween 5 to 10 mm |
| B. | etween 10 to 15 mm |
| C. | etween 15 to 20 mm |
| D. | etween 25 to 35 mm |
| Answer» E. | |
| 42. |
An ammeter is a |
| A. | econdary instrument |
| B. | bsolute instrument |
| C. | ecording instrument |
| D. | ntegrating instrument |
| Answer» B. bsolute instrument | |
| 43. |
Hot rolled sheets have ______ value of permeability |
| A. | ero |
| B. | ow |
| C. | igh |
| D. | one of the above |
| Answer» C. igh | |
| 44. |
It is required to measure the true open circuit e.m.f. of a battery. The best device is |
| A. | .C. voltmeter |
| B. | mmeter and a known resistance |
| C. | .'potentiometer |
| D. | one of the above |
| Answer» D. one of the above | |
| 45. |
To avoid the effect of stray magnetic field in A.C. bridges we can use |
| A. | agnetic screening |
| B. | agner earthing device |
| C. | ave filters |
| D. | ny of the above |
| Answer» B. agner earthing device | |
| 46. |
_______ brushes are fragile and cause excessive wear of commutator, |
| A. | atural graphite |
| B. | ard carbon |
| C. | lectro graphitic |
| D. | etal graphite |
| Answer» B. ard carbon | |
| 47. |
Which of the following is measured by using a vector voltmeter ? |
| A. | mplifier gain and phase shift |
| B. | iller transfer functions |
| C. | omplex insersion loss |
| D. | ll of the above |
| Answer» E. | |
| 48. |
A voltage of about 200 V can be measured |
| A. | irectly by a D.C. potentiometer |
| B. | D.C. potentiometer in conjunction with a volt ratio box |
| C. | D.C. potentiometer in conjunction with a known resistance |
| D. | one of the above |
| Answer» C. D.C. potentiometer in conjunction with a known resistance | |
| 49. |
The design of mechanical parts is particularly important in case of _____ speed machines. |
| A. | ow |
| B. | edium |
| C. | igh |
| D. | ny of the above |
| Answer» D. ny of the above | |
| 50. |
A practical formula for determining the thickness of insulation between low voltage and high voltage windings is |
| A. | + 0.2 kV mm |
| B. | + 0.5 kV mm |
| C. | + 0.7 kV mm |
| D. | + 0.9 kV mm |
| Answer» E. | |