MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Dc Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What will happen to the speed of a series motor if the temperature of armature resistance is increased? |
| A. | Not change |
| B. | Decreases |
| C. | Increases |
| D. | Cannot be determined |
| Answer» C. Increases | |
| 2. |
Where diverters are used? |
| A. | In shunt motors |
| B. | In series motors |
| C. | In both motors |
| D. | All other motors except shunt and series motors |
| Answer» C. In both motors | |
| 3. |
In series-parallel speed control method ______________ |
| A. | Speed given by parallel connection is more |
| B. | Speed given by series connection is more |
| C. | Both speeds can be equal |
| D. | Will depend on other parameters |
| Answer» B. Speed given by series connection is more | |
| 4. |
Which of the following method will not give many speed values for a DC series motor? |
| A. | Diverter |
| B. | Series-parallel |
| C. | Field tapped |
| D. | All field control methods will give many speed values |
| Answer» C. Field tapped | |
| 5. |
In tapped field control method ____________ |
| A. | A variable resistor is connected in parallel |
| B. | A variable resistor is connected in series |
| C. | Field winding is made with more out pins |
| D. | Another field winding is added with the previous one |
| Answer» D. Another field winding is added with the previous one | |
| 6. |
For higher diverter resistance, speed-torque characteristic will lie ____________ |
| A. | Above speed-torque characteristic of lower resistance |
| B. | Below speed-torque characteristic of lower resistance |
| C. | On the speed-torque characteristic of lower resistance |
| D. | Cannot say |
| Answer» C. On the speed-torque characteristic of lower resistance | |
| 7. |
Why it is advisable to use inductively wound diverter resistor? |
| A. | To make speed control on more range |
| B. | For long-life of machine |
| C. | Cost efficient |
| D. | To avoid oscillations in speed |
| Answer» E. | |
| 8. |
In diverter resistor field control method of DC series motor, variable resistor is added ________ |
| A. | In parallel with field |
| B. | In series with field |
| C. | In parallel with armature |
| D. | In parallel with load |
| Answer» B. In series with field | |
| 9. |
For large motors what is the ratio of compensating winding is required for increasing the speed of the motor? |
| A. | 2:1 |
| B. | 4:1 |
| C. | 6:1 |
| D. | 8:1 |
| Answer» B. 4:1 | |
| 10. |
For speed reversal, field control method is suitable. |
| A. | True |
| B. | False |
| Answer» C. | |
| 11. |
Which of the following is not the method of speed control in DC series motor? |
| A. | Diverter |
| B. | Tapped-field control |
| C. | Variable resistance in series with armature |
| D. | Series- parallel control |
| Answer» D. Series- parallel control | |
| 12. |
The speed of a motor falls from 1200 rpm at no-load to 1050 rpm at rated load. The speed regulation of the motor is ____________ |
| A. | 12.36% |
| B. | 14.28% |
| C. | 16.77% |
| D. | 18.84% |
| Answer» C. 16.77% | |
| 13. |
In variable speed motor ____________ |
| A. | Stronger commutating field is needed at low speed than at high speed |
| B. | Weaker commutating field is needed at low speed than at high speed |
| C. | Same commutating field is needed at low speed and at high speed |
| D. | Cannot be determined |
| Answer» C. Same commutating field is needed at low speed and at high speed | |
| 14. |
Which of the following DC motor has the poorest speed control? |
| A. | Differentially compounded motor |
| B. | Cumulatively compounded motor |
| C. | Shunt motor |
| D. | Series motor |
| Answer» E. | |