McqMate
Chapters
| 1. |
No-load speed of which of the following motor will be highest ? |
| A. | Shunt motor |
| B. | Series motor |
| C. | Cumulative compound motor |
| D. | Differentiate compound motor |
| Answer» B. Series motor | |
| 2. |
The direction of rotation of a D.C. series motor can be changed by |
| A. | interchanging supply terminals |
| B. | interchanging field terminals |
| C. | either of (a) and (b) above |
| D. | None of the above |
| Answer» B. interchanging field terminals | |
| 3. |
Which of the following application requires high starting torque ? |
| A. | Lathe machine |
| B. | Centrifugal pump |
| C. | Locomotive |
| D. | Air blower |
| Answer» C. Locomotive | |
| 4. |
If a D.C. motor is to be selected for conveyors, which rriotor would be preferred ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Differentially compound motor |
| D. | Cumulative compound motor |
| Answer» A. Series motor | |
| 5. |
Which D.C. motor will be preferred for machine tools ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulative compound motor |
| D. | Differential compound motor |
| Answer» B. Shunt motor | |
| 6. |
Differentially compound D.C. motors can find applicationsrequiring |
| A. | high starting torque |
| B. | low starting torque |
| C. | variable speed |
| D. | frequent on-off cycles |
| Answer» B. low starting torque | |
| 7. |
Which D.C. motor is preferred for elevators ? |
| A. | Shunt motor |
| B. | Series motor |
| C. | Differential compound motor |
| D. | Cumulative compound motor |
| Answer» D. Cumulative compound motor | |
| 8. |
If the field of a D.C. shunt motor gets opened while motor is running |
| A. | the speed of motor will be reduced % |
| B. | the armature current will reduce |
| C. | the motor will attain dangerously high speed 1 |
| D. | the motor will continue to nuvat constantspeed |
| Answer» C. the motor will attain dangerously high speed 1 | |
| 9. |
Starters are used with D.C. motors because |
| A. | these motors have high starting torque |
| B. | these motors are not self-starting |
| C. | back e.m.f. of these motors is zero initially |
| D. | to restrict armature current as there is no back e.m.f. whilestarting |
| Answer» D. to restrict armature current as there is no back e.m.f. whilestarting | |
| 10. |
In D.C. shunt motors as load is reduced |
| A. | the speed will increase abruptly |
| B. | the speed will increase in proportion to reduction in load |
| C. | the speed will remain almost/constant |
| D. | the speed will reduce |
| Answer» C. the speed will remain almost/constant | |
| 11. |
A D.C. series motor is that which |
| A. | has its field winding consisting of thick wire and lessturns |
| B. | has a poor torque |
| C. | can be started easily without load |
| D. | has almost constant speed |
| Answer» A. has its field winding consisting of thick wire and lessturns | |
| 12. |
For starting a D.C. motor a starter is required because |
| A. | it limits the speed of the motor |
| B. | it limits the starting current to a safe value |
| C. | it starts the motor |
| D. | none of the above |
| Answer» B. it limits the starting current to a safe value | |
| 13. |
The type of D.C. motor used for shears and punches is |
| A. | shunt motor |
| B. | series motor |
| C. | differential compoutid D.C. motor |
| D. | cumulative compound D.C. motor |
| Answer» D. cumulative compound D.C. motor | |
| 14. |
If a D.C. motor is connected across the A.C. supply it will |
| A. | run at normal speed |
| B. | not run |
| C. | run at lower speed |
| D. | burn due to heat produced in the field winding by .eddy currents |
| Answer» D. burn due to heat produced in the field winding by .eddy currents | |
| 15. |
To get the speed of D.C, motor below the normal without wastage of electrical energy is used. |
| A. | Ward Leonard control |
| B. | rheostatic control |
| C. | any of the above method |
| D. | none of the above method |
| Answer» A. Ward Leonard control | |
| 16. |
When two D.C. series motors are connected in parallel, the resultant speed is |
| A. | more than the normal speed |
| B. | loss than the normal speed |
| C. | normal speed |
| D. | zero |
| Answer» C. normal speed | |
| 17. |
The speed of a D.C. shunt motor more than its full-load speed can be obtained by |
| A. | decreasing the field current |
| B. | increasing the field current |
| C. | decreasing the armature current |
| D. | increasing the armature current |
| Answer» A. decreasing the field current | |
| 18. |
In a D.C. shunt motor, speed is |
| A. | independent of armature current |
| B. | directly proportional to the armature current |
| C. | proportional to the square of the current |
| D. | inversely proportional to the armature current |
| Answer» A. independent of armature current | |
| 19. |
A direct on line starter is used: for starting motors |
| A. | iip to 5 H.P. |
| B. | up to 10 H.P. |
| C. | up to 15 H.P. |
| D. | up to 20 H.P. |
| Answer» A. iip to 5 H.P. | |
| 20. |
What will happen if the back e.m.f. of a D.C. motor vanishes suddenly? |
| A. | The motor will stop |
| B. | The motor will continue to run |
| C. | The armature may burn |
| D. | The motor will run noisy |
| Answer» C. The armature may burn | |
| 21. |
In case of D.C. shunt motors the speed is dependent on back e.m.f. only because |
| A. | back e.m.f. is equal to armature drop |
| B. | armature drop is negligible |
| C. | flux is proportional to armature current |
| D. | flux is practically constant in D:C. shuntmotors |
| Answer» D. flux is practically constant in D:C. shuntmotors | |
| 22. |
In a D.C. shunt motor, under the conditions of maximum power, the current inthe armature will be |
| A. | almost negligible |
| B. | rated full-load current |
| C. | less than full-load current |
| D. | more than full-load current |
| Answer» D. more than full-load current | |
| 23. |
These days D.C. motors are widely used in |
| A. | pumping sets |
| B. | air compressors |
| C. | electric traction |
| D. | machine shops |
| Answer» C. electric traction | |
| 24. |
By looking at which part of the motor, it can be easily confirmedthat a particular motor is D.C. motor? |
| A. | Frame |
| B. | Shaft |
| C. | Commutator |
| D. | Stator |
| Answer» C. Commutator | |
| 25. |
In which of the following applications D.C. series motor is invariably tried? |
| A. | Starter for a car |
| B. | Drive for a water pump |
| C. | Fan motor |
| D. | Motor operation in A.C. or D.C. |
| Answer» A. Starter for a car | |
| 26. |
In D.C. machines fractional pitch winding is used |
| A. | to improve cooling |
| B. | to reduce copper losses |
| C. | to increase the generated e.m.f. |
| D. | to reduce the sparking |
| Answer» D. to reduce the sparking | |
| 27. |
A three point starter is considered suitable for |
| A. | shunt motors |
| B. | shunt as well as compound motors |
| C. | shunt, compound and series motors |
| D. | all D.C. motors |
| Answer» B. shunt as well as compound motors | |
| 28. |
In case-the conditions for maximum power for a D.C. motor are established,the efficiency of the motor will be |
| A. | 100% |
| B. | around 90% |
| C. | anywhere between 75% and 90% |
| D. | less than 50% |
| Answer» D. less than 50% | |
| 29. |
The ratio of starting torque to full-load torque is least in case of |
| A. | series motors |
| B. | shunt motors |
| C. | compound motors |
| D. | none of the above |
| Answer» B. shunt motors | |
| 30. |
In D.C. motor which of the following can sustain the maximum temperature rise? |
| A. | Slip rings |
| B. | Commutator |
| C. | Field winding |
| D. | Armature winding |
| Answer» C. Field winding | |
| 31. |
Which of the following law/rule can he used to determine the direction of rotationof D.C. motor ? |
| A. | Lenz's law |
| B. | Faraday's law |
| C. | Coloumb'slaw |
| D. | Fleming's left-hand rule |
| Answer» D. Fleming's left-hand rule | |
| 32. |
Which of the following load normally needs starting torque more than therated torque? |
| A. | Blowers |
| B. | Conveyors |
| C. | Air compressors |
| D. | Centrifugal pumps |
| Answer» B. Conveyors | |
| 33. |
The starting resistance of a D.C. motor is generally |
| A. | low |
| B. | around 500 Q |
| C. | 1000 Q |
| D. | infinitely large |
| Answer» A. low | |
| 34. |
The speed of a D.C. series motor is |
| A. | proportional to the armature current |
| B. | proportional to the square of the armature current |
| C. | proportional to field current |
| D. | inversely proportional to the armature current |
| Answer» D. inversely proportional to the armature current | |
| 35. |
In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to |
| A. | 100% of the previous value |
| B. | 50% of the previous value |
| C. | 25% of the previous value |
| D. | 10% of the previous value |
| Answer» C. 25% of the previous value | |
| 36. |
The current drawn by the armature of D.C. motor is directly proportional to |
| A. | the torque required |
| B. | the speed of the motor |
| C. | the voltage across the terminals |
| D. | none of the above |
| Answer» A. the torque required | |
| 37. |
The power mentioned on the name plate of an electric motor indicates |
| A. | the power drawn in kW |
| B. | the power drawn in kVA |
| C. | the gross power |
| D. | the output power available at the shaft |
| Answer» D. the output power available at the shaft | |
| 38. |
Which D.C. motor has got maximum self loading property? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded 'motor |
| D. | Differentially compounded motor |
| Answer» D. Differentially compounded motor | |
| 39. |
Which D.C. motor will be suitable alongwith flywheel for intermittent light andheavy loads? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded motor |
| D. | Differentially compounded motor |
| Answer» C. Cumulatively compounded motor | |
| 40. |
If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens |
| A. | nothing will happen to th£ motor |
| B. | this will make armature to take heavy current, possibly burning it |
| C. | this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses |
| D. | motor will run at very slow speed |
| Answer» C. this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses | |
| 41. |
D.C. series motors are used |
| A. | where load is constant |
| B. | where load changes frequently |
| C. | where constant operating speed is needed |
| D. | in none of the above situations. |
| Answer» D. in none of the above situations. | |
| 42. |
For the same H.P. rating and full load speed, following motor has poor starting torque |
| A. | shunt |
| B. | series |
| C. | differentially compounded |
| D. | cumulativelyc'ompounded |
| Answer» C. differentially compounded | |
| 43. |
In case of conductively compensated D.C. series motors, the compensating winding is provided |
| A. | as separately wound unit |
| B. | in parallel with armature winding |
| C. | in series with armature winding |
| D. | in parallel with field winding |
| Answer» C. in series with armature winding | |
| 44. |
Sparking at the commutator of a D.C. motor may result in |
| A. | damage to commutator segments |
| B. | damage to commutator insulation |
| C. | increased power consumption |
| D. | all of the above |
| Answer» D. all of the above | |
| 45. |
Which of the following motor is preferred for operation in highly explosive atmosphere ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Air motor |
| D. | Battery operated motor |
| Answer» C. Air motor | |
| 46. |
If the supply voltage for a D.C. motor is increased, which of the following willdecrease ? |
| A. | Starting torque |
| B. | Operating speed |
| C. | Full-load current |
| D. | All of the above |
| Answer» C. Full-load current | |
| 47. |
Which one of the following is not the function of pole shoes in a D.C. machine ? |
| A. | To reduce eddy current loss |
| B. | To support the field coils |
| C. | To spread out flux for better unifor-mity |
| D. | To reduce the reluctance of the mag-netic path |
| Answer» A. To reduce eddy current loss | |
| 48. |
The mechanical power developed by a shunt motor will be maximum when theratio of back e.m.f. to applied voltage is |
| A. | 4.0 |
| B. | 2.0 |
| C. | 1.0 |
| D. | 0.5 |
| Answer» D. 0.5 | |
| 49. |
For which of the following applications a D.C. motor is preferred over an A.C. motor? |
| A. | Low speed operation |
| B. | High speed operation |
| C. | Variable speed operation |
| D. | Fixed speed operation |
| Answer» C. Variable speed operation | |
| 50. |
In D.C. machines the residual magnetism is of the order of |
| A. | 2 to 3 per cent |
| B. | 10 to 15 per cent |
| C. | 20 to 25 per cent |
| D. | 50 to 75 per cent |
| Answer» A. 2 to 3 per cent | |
| 51. |
Which D.C. motor is generally preferred for cranes and hoists ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded motor |
| D. | Differentially compounded motor |
| Answer» A. Series motor | |
| 52. |
Three point starter can be used for |
| A. | series motor only |
| B. | shunt motor only |
| C. | compound motor only |
| D. | both shunt and compound motor |
| Answer» D. both shunt and compound motor | |
| 53. |
Sparking, is discouraged in a D.C. motor because |
| A. | it increases the input power con-sumption |
| B. | commutator gets damaged |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» B. commutator gets damaged | |
| 54. |
Speed control by Ward Leonard method gives uniform speed variation |
| A. | in one direction |
| B. | in both directions |
| C. | below normal speed only |
| D. | above normal speed only. |
| Answer» B. in both directions | |
| 55. |
Flywheel is used with D.C. compound motor to reduce the peak demand by the motor, compound motor will have to be |
| A. | level compounded |
| B. | under compounded |
| C. | cumulatively compounded |
| D. | differentially compounded |
| Answer» C. cumulatively compounded | |
| 56. |
Following motor is used where high starting torque and wide speed range control is required. |
| A. | Single phase capacitor start |
| B. | Induction motor |
| C. | Synchronous motor |
| D. | D.C. motor |
| Answer» D. D.C. motor | |
| 57. |
In a differentially compounded D.C. motor, if shunt field suddenly opens |
| A. | the motor will first stop and then run in opposite direction as series motor |
| B. | the motor will work as series motor and run at slow speed in the same direction |
| C. | the motor will work as series motor and run at high speed in the samedirection |
| D. | the motor will not work and come to stop |
| Answer» A. the motor will first stop and then run in opposite direction as series motor | |
| 58. |
Which of the following motor has the poorest speed regulation ? |
| A. | Shunt motor |
| B. | Series motor |
| C. | Differential compound motor |
| D. | Cumulative compound motor |
| Answer» B. Series motor | |
| 59. |
Buses, trains, trolleys, hoists, cranes require high starting torque and therefore make use of |
| A. | D.C. series motor |
| B. | D.C. shunt motor |
| C. | induction motor |
| D. | all of above motors |
| Answer» A. D.C. series motor | |
| 60. |
As -the load is increased the speed of D.C. shunt motor will |
| A. | reduce slightly |
| B. | increase slightly |
| C. | increase proportionately |
| D. | remains unchanged |
| Answer» A. reduce slightly | |
| 61. |
The armature torque of the D.C. shunt motor is proportional to |
| A. | field flux only |
| B. | armature current only |
| C. | both (a) and (b) |
| D. | none of the above |
| Answer» B. armature current only | |
| 62. |
Which of the following method of speed control of D.C. machine will offer minimum efficiency ? |
| A. | Voltage control method |
| B. | Field control method |
| C. | Armature control method |
| D. | All above methods |
| Answer» C. Armature control method | |
| 63. |
Usually wide and sensitive speed control is desired in case of |
| A. | centrifugal pumps |
| B. | elevators |
| C. | steel rolling mills |
| D. | colliery winders |
| Answer» D. colliery winders | |
| 64. |
The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load.The speed regulation of the motor is |
| A. | 2.36% |
| B. | 4.76% |
| C. | 6.77% |
| D. | 8.84% |
| Answer» B. 4.76% | |
| 65. |
The armature voltage control of D.C. motor provides |
| A. | constant torque drive |
| B. | constant voltage drive |
| C. | constant current drive |
| D. | none of the above |
| Answer» A. constant torque drive | |
| 66. |
As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit |
| A. | a resistance is connected in series with armature |
| B. | a resistance is connected parallel to the armature |
| C. | armature is temporarily open circuited |
| D. | a high value resistor is connected across the fieldwinding |
| Answer» A. a resistance is connected in series with armature | |
| 67. |
The speed of a D.C. shunt motor can be increased by |
| A. | increasing the resistance in armature circuit |
| B. | increasing the resistance in field circuit |
| C. | reducing the resistance in the field circuit |
| D. | reducing the resistance in the armature circuit |
| Answer» B. increasing the resistance in field circuit | |
| 68. |
If I2 be the armature current, then speed of a D.C. shunt motor is |
| A. | independent of Ia |
| B. | proportional to la |
| C. | varies as (Ia) |
| D. | varies as la |
| Answer» A. independent of Ia | |
| 69. |
In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will |
| A. | remain unchanged |
| B. | reduce to one-fourth value |
| C. | increase four folds |
| D. | be doubled |
| Answer» A. remain unchanged | |
| 70. |
At the instant of starting when a D.C. motor is put on supply, it behaveslike |
| A. | a highly resistive circuit |
| B. | a low resistance circuit |
| C. | a capacitive circuit |
| D. | none of the above |
| Answer» B. a low resistance circuit | |
| 71. |
The speed of a D.C. motor can be varied by varying |
| A. | field current |
| B. | applied voltage |
| C. | resistance in series with armature |
| D. | any of the above |
| Answer» D. any of the above | |
| 72. |
Which one of the following is not necessarily the advantage of D.C. motors over A.C. motors ? |
| A. | Low cost |
| B. | Wide speed range |
| C. | Stability |
| D. | High starting torque. |
| Answer» A. Low cost | |
| 73. |
For a D.C. shunt motor if the excitation is changed |
| A. | torque will remain constant |
| B. | torque will change but power will remain constant |
| C. | torque and power both will change |
| D. | torque, power and speed, all will change |
| Answer» B. torque will change but power will remain constant | |
| 74. |
Which motor has the poorest speed control? |
| A. | Differentially compounded motor |
| B. | Cumulatively compoundedmotor |
| C. | Shunt motor |
| D. | Series motor |
| Answer» D. Series motor | |
| 75. |
The plugging gives the |
| A. | zero torque braking |
| B. | smallest torque braking |
| C. | highest torque braking |
| D. | none of the above |
| Answer» C. highest torque braking | |
| 76. |
The armature voltage control of D.C. motor provides |
| A. | constant voltage drive |
| B. | constant current drive |
| C. | constant torque drive |
| D. | none of the above |
| Answer» C. constant torque drive | |
| 77. |
If a D.C. motor designed for 40°C ambient temperature is to be used for 50°C ambient temperature, then the motor |
| A. | of lower H.P. should be selected |
| B. | of higher H.P. should be selected |
| C. | can be used for 50°C ambient temperature also |
| D. | is to be derated by a factor recom-mended by manufacturer and select the next higher H.P. motor |
| Answer» D. is to be derated by a factor recom-mended by manufacturer and select the next higher H.P. motor | |
| 78. |
If the terminals of armature of D.C. motor are interchanged, this action will offer following kind of braking |
| A. | regenerative |
| B. | plugging |
| C. | dynamic braking |
| D. | none of the above |
| Answer» B. plugging | |
| 79. |
Which of the following motors one will choose to drive the rotary compressor ? |
| A. | D.C. shunt motor |
| B. | D.C. series motor |
| C. | Universal motor |
| D. | Synchronous motor |
| Answer» D. Synchronous motor | |
| 80. |
If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will |
| A. | increase |
| B. | decrease |
| C. | remain same |
| D. | become zero |
| Answer» A. increase | |
| 81. |
Why are the D.C. motors preferred for traction applications ? |
| A. | Torque and speed are inversely proportional to armature current |
| B. | Torque is proportional to armature current |
| C. | Torque is proportional to square root of armature current |
| D. | The speed is inversely proportional to the torque and the torque is proportional to square of armature current |
| Answer» D. The speed is inversely proportional to the torque and the torque is proportional to square of armature current | |
| 82. |
Which of the following motors is usually used in house-hold refrigerators ? |
| A. | D.C. shunt motor |
| B. | D.C. series motor |
| C. | Single phase induction motor (split phase start or induction run motor) |
| D. | Reluctance motor |
| Answer» C. Single phase induction motor (split phase start or induction run motor) | |
| 83. |
Which of the following motors is most suitable for signalling devices and many kinds of timers ? |
| A. | D.C. shunt motor |
| B. | D.C. series motor |
| C. | Induction motor |
| D. | Reluctance motor |
| Answer» D. Reluctance motor | |
| 84. |
Which motor should not be started on no-load ? |
| A. | Series motor |
| B. | Shunt motor |
| C. | Cumulatively compounded motor |
| D. | Differentially compounded motor. |
| Answer» A. Series motor | |
| 85. |
Ward-Leonard control is basically a |
| A. | voltage control method |
| B. | field divertor method |
| C. | field control method |
| D. | armature resistance control method |
| Answer» A. voltage control method | |
| 86. |
For constant torque drive which speed control method is preferred ? |
| A. | Field control |
| B. | Armature voltage control |
| C. | Shunt armature control |
| D. | Mechanical loading system |
| Answer» B. Armature voltage control | |
| 87. |
In Ward-Leonard control the lower limit of speed is imposed by |
| A. | residual magnetism of the generator |
| B. | core losses of motor |
| C. | mechanical losses of motor and gen¬erator together |
| D. | all of the above |
| Answer» A. residual magnetism of the generator | |
| 88. |
The main disadvantage of the Ward-Leonard control method is |
| A. | high initial cost |
| B. | high maintenance cost |
| C. | low efficiency at Hght loads |
| D. | all of the above |
| Answer» D. all of the above | |
| 89. |
Regenerative method of braking is based on that |
| A. | back e.m.f. is less than the applied voltage |
| B. | back e.m.f. is equal to the applied voltage |
| C. | back e.m.f. of rotor is more than the applied voltage |
| D. | none of the above |
| Answer» B. back e.m.f. is equal to the applied voltage | |
| 90. |
The hysteresis loss in a D.C. machine least depends on |
| A. | Frequency of magnetic reversals |
| B. | Maximum value of flux density |
| C. | Volume and grade of iron |
| D. | Rate of flow of ventilating air |
| Answer» D. Rate of flow of ventilating air | |
| 91. |
In a D.C. generator all of the following could be the effects of iron losses except |
| A. | Loss of efficiency |
| B. | Excessive heating of core |
| C. | Increase in terminal voltage |
| D. | Rise in temperature of ventilating air |
| Answer» C. Increase in terminal voltage | |
| 92. |
The losses occurring in a D.C. generator are given below. Which loss is likely to have highest proportion at rated load of the generator ? |
| A. | hysteresis loss |
| B. | field copper loss |
| C. | armature copper loss |
| D. | eddy current loss |
| Answer» C. armature copper loss | |
| 93. |
Which of the following loss in a D.C. generator varies significantly with the load current ? |
| A. | Field copper loss |
| B. | Windage loss |
| C. | Armature copper loss |
| D. | None of the above |
| Answer» C. Armature copper loss | |
| 94. |
Torque developed by a D.C. motor depends upon |
| A. | magnetic field |
| B. | active length of the conductor |
| C. | current flow through the conductors |
| D. | all above factors |
| Answer» D. all above factors | |
| 95. |
D.C. shunt motors are used for driving |
| A. | trains |
| B. | cranes |
| C. | hoists |
| D. | machine tools |
| Answer» D. machine tools | |
| 96. |
In a manual shunt motor starter |
| A. | over load relay is connected in series and no volt relay in parallel with the load |
| B. | over load relay is connected in paral¬lel and no volt relay in series with the load |
| C. | over load relay and no volt relay are both connected in series with the load |
| D. | over load relay and no volt relay are both connected in parallel with the load |
| Answer» A. over load relay is connected in series and no volt relay in parallel with the load | |
| 97. |
Which of the following steps is likely to result in reduction of hysteresis loss in a D.C. generator ? |
| A. | Providing laminations in armature core |
| B. | Providing laminations in stator |
| C. | Using non-magnetic material for frame |
| D. | Using material of low hysteresis co-efficient for armature corematerial |
| Answer» D. Using material of low hysteresis co-efficient for armature corematerial | |
| 98. |
Which of the following loss in a D.C. generator is dissipated in the form of heat? |
| A. | Mechanical loss |
| B. | Core loss |
| C. | Copper loss |
| D. | All of the above |
| Answer» D. All of the above | |
| 99. |
Which of the following losses are significantly reduced by laminating the core of a D.C. generator ? |
| A. | Hysteresis losses |
| B. | Eddy current losses |
| C. | Copper losses |
| D. | Windage losses |
| Answer» B. Eddy current losses | |
| 100. |
The total losses in a well designed D.C. generator of 10 kW will be nearly |
| A. | 100 W |
| B. | 500 W |
| C. | 1000 W |
| D. | 1500 W |
| Answer» B. 500 W | |
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