MCQOPTIONS
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MCQOPTIONS
This section includes 11 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. |
A_STARTER_IS_REQUIRED_FOR_A_220-V_SHUNT_MOTOR._THE_MAXIMUM_ALLOWABLE_CURRENT_IS_55_A_AND_THE_MINIMUM_CURRENT_IS_ABOUT_35_A._THE_ARMATURE_RESISTANCE_OF_THE_MOTOR_IS_0.4_‚ÄÖ√Ñ√∂‚ÀÖ√´¬¨‚ÀÇ._WHAT_WILL_BE_THE_NUMBER_OF_SECTIONS_OF_STARTER_RESISTANCE_REQUIRED??$# |
| A. | 5 |
| B. | 4 |
| C. | 6 |
| D. | 8 |
| Answer» D. 8 | |
| 2. |
Four-point starter is used when ______________$ |
| A. | Motor field current is varied in narrow range |
| B. | Motor speed is varied in small range |
| C. | Motor field current is varied over wide range |
| D. | Can be used anywhere |
| Answer» D. Can be used anywhere | |
| 3. |
γ is given as 1.585. Resistance at maximum allowable current is given equal to 4 Ω, what is the 5th step resistance?$# |
| A. | 0.235 |
| B. | 0.370 |
| C. | 1.476 |
| D. | 2 |
| Answer» B. 0.370 | |
| 4. |
In shunt and compound motor starting the shunt field should be made on with full starting resistance in ___________? |
| A. | Series with field |
| B. | Parallel with field |
| C. | Series with armature |
| D. | Parallel with armature |
| Answer» D. Parallel with armature | |
| 5. |
Motor will start quickly when used without starter. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 6. |
What will happen if DC motor is used without starter? |
| A. | Heavy sparking at brushes |
| B. | It’ll start smoothly |
| C. | Will not start at all |
| D. | Depends on load |
| Answer» B. It‚Äö√Ñ√∂‚àö√ë‚àö¬•ll start smoothly | |
| 7. |
In a manual shunt motor starter relay positions are ________________________ |
| A. | Over load relay is connected in series and no volt relay in parallel with the load |
| B. | Over load relay is connected in parallel 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» B. Over load relay is connected in parallel and no volt relay in series with the load | |
| 8. |
The starting resistance of a DC shunt motor is generally ______ |
| A. | low |
| B. | Around 0.5 kΩ |
| C. | Around 5 kΩ |
| D. | Infinitely large |
| Answer» B. Around 0.5 k‚Äö√Ñ√∂‚àö√´¬¨‚àÇ | |
| 9. |
A three-point starter is used for _________ |
| A. | Shunt motors |
| B. | Shunt as well as compound motors |
| C. | Shunt, compound and series motors |
| D. | Not for DC motors |
| Answer» C. Shunt, compound and series motors | |
| 10. |
For which motors DOL starter can be used? |
| A. | Up to 5 H.P |
| B. | Up to 10 H.P |
| C. | Up to 15 H.P |
| D. | Up to 20 H.P |
| Answer» B. Up to 10 H.P | |
| 11. |
Why starters are required in a DC motor? |
| A. | Back emf of these motors is zero initially |
| B. | These motors are not self-starting |
| C. | These motors have high starting torque |
| D. | To restrict armature current as there is no back emf at starting |
| Answer» E. | |