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This section includes 9 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. |
From magnetization characteristic at If = 7.1 A, Ea = 225 V at 1000 rpm. What will be the terminal voltage at speed 950 rpm? |
A. | 225 V |
B. | 235 V |
C. | 214 V |
D. | 220 V |
Answer» D. 220 V | |
2. |
For a given compound DC machine, Net field current obtained from characteristic is equal to 7.5 A, where shunt field current is equal to 5 A, armature current is 505 A, demagnetizing current equal to 0.95 A and shunt field winding of 1000 turns at rated speed of 1000 rpm. What will be the series field turns? |
A. | 7 |
B. | 8 |
C. | 5 |
D. | 9 |
Answer» B. 8 | |
3. |
From magnetization characteristic at If = 7.1 A, Ea = 225 V at 1000 rpm. What will be the terminal voltage at speed 950 rpm? |
A. | 225 V |
B. | 235 V |
C. | 214 V |
D. | 220 V |
Answer» D. 220 V | |
4. |
External characteristics of DC shunt motor lies in ______________ |
A. | 1<sup>st</sup> quadrant |
B. | 2<sup>nd</sup> quadrant |
C. | 1<sup>st</sup> and 2<sup>nd</sup> quadrant |
D. | 4<sup>th</sup> quadrant |
Answer» D. 4<sup>th</sup> quadrant | |
5. |
How demagnetization effect of armature reaction is shown graphically? |
A. | By shifting origin towards +ve y axis |
B. | By shifting origin towards +ve x axis |
C. | By shifting origin towards -ve y axis |
D. | By shifting origin towards -ve x axis |
Answer» E. | |
6. |
For determining IaRa maximum _____________ |
A. | Distance between R<sub>f</sub> line and v+ I<sub>a</sub>R<sub>a</sub> line is taken |
B. | Distance between OCC and v+ I<sub>a</sub>R<sub>a</sub> line is taken |
C. | Maximum Distance between OCC and v+ I<sub>a</sub>R<sub>a</sub> line is taken |
D. | Can’t calculated graphically |
Answer» D. Can‚Äö√Ñ√∂‚àö√ë‚àö¬•t calculated graphically | |
7. |
How armature resistance effect is shown graphically? |
A. | By adding I<sub>a</sub>R<sub>a</sub> product horizontally with R<sub>f</sub> line |
B. | By subtracting I<sub>a</sub>R<sub>a</sub> product vertically with R<sub>f</sub> line |
C. | By adding I<sub>a</sub>R<sub>a</sub> product vertically with R<sub>f</sub> line |
D. | By subtracting I<sub>a</sub>R<sub>a</sub> product horizontally with R<sub>f</sub> line |
Answer» D. By subtracting I<sub>a</sub>R<sub>a</sub> product horizontally with R<sub>f</sub> line | |
8. |
Rf line intersects with OCC in ________ |
A. | 1<sup>st</sup> quadrant |
B. | 2<sup>nd</sup> quadrant |
C. | 3<sup>rd</sup> quadrant |
D. | 4<sup>th</sup> quadrant |
Answer» B. 2<sup>nd</sup> quadrant | |
9. |
No load point of DC generator is __________ |
A. | Intersection of OCC and Rf line |
B. | Point on the Y axis at rated field current |
C. | Point on the X axis at rated terminal voltage |
D. | Can’t find through graphical interpretation |
Answer» B. Point on the Y axis at rated field current | |