Mcqs

DC Machines Mcqs

Our 1000+ DC Machines MCQs (Multiple Choice Questions and Answers) focus on all areas of DC Machines covering 100+ topics. These topics are chosen from a collection of the most authoritative and best reference books on DC Machines. One should spend 1 hour daily practicing these MCQs for 2-3 months to learn and assimilate DC Machines subjects comprehensively. This way of systematic learning will prepare anyone easily for DC Machines exams, contests, online tests, quizzes, MCQ-tests, viva-voce, interviews, and certifications.

 

DC Machines Multiple Choice Questions Highlights

  • 1000+ Multiple Choice Questions & Answers (MCQs) in DC Machines with a detailed explanation of every question.
  • These MCQs cover theoretical concepts, true-false(T/F) statements, fill-in-the-blanks, and match the following style statements.
  • These MCQs also cover numerical as well as diagram-oriented MCQs.
  • These MCQs are organized chapterwise and each Chapter is further organized topicwise.
  • Every MCQ set focuses on a specific topic of a given Chapter in DC Machines Subject.

 

Who should Practice DC Machines MCQs?

  • Students who are preparing for college tests and exams such as mid-term tests and semester tests on DC Machines.
  • Students who are preparing for Online/Offline Tests/Contests in DC Machines.
  • Students who wish to sharpen their knowledge of DC Machines Subject.
  • Anyone preparing for Aptitude test in DC Machines.
  • Anyone preparing for interviews (campus/off-campus interviews, walk-in interviews, and company interviews).
  • Anyone preparing for entrance examinations and other competitive examinations.
  • All - Experienced, Freshers and College / School Students.
Latest Popular
Q:

In current commutation, in chopper circuit we use _____________

A) 2 auxiliary thyristors B) 2 diodes
C) 1 auxiliary thyristor D) 2 auxiliary thyristors and 2 diodes
 
Answer & Explanation Answer: D) 2 auxiliary thyristors and 2 diodes

Explanation: Two auxiliary thyristors are connected in the chopper circuit along with two diodes, one inductor, one capacitor in series with the voltage supply which is then connected in parallel with diode and DC motor armature.

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Category: Electronics & Electrical MCQs
Sub Category: DC Machines Mcqs

81
Q:

In voltage commutation, in chopper circuit we use _____________

A) 2 auxiliary thyristors B) 2 diodes
C) 1 auxiliary thyristor D) Many diodes
 
Answer & Explanation Answer: A) 2 auxiliary thyristors

Explanation: Two auxiliary thyristors are connected in the chopper circuit along with one diode, one inductor, one capacitor in series with the voltage supply which is then connected in parallel with diode and DC motor armature.

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Category: Electronics & Electrical MCQs
Sub Category: DC Machines Mcqs

63
Q:

Which of the following is not the method of auxiliary commutation?

A) Voltage commutation B) Resistance commutation
C) Current commutation D) Load commutation
 
Answer & Explanation Answer: B) Resistance commutation

Explanation: Thyristor in a chopper has to be turned off by auxiliary commutation. This can be done by two methods-Forced commutation and Load commutation. Forced commutation can also be done by two ways, current and voltage.

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Category: Electronics & Electrical MCQs
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69
Q:

What is the formula for step up chopper?

A) V(1-α) B) V/(1-α)
C) αV D) v/α
 
Answer & Explanation Answer: B) V/(1-α)

Explanation: With the help of conventional chopper one can reduce the average voltage, so by doing slight modification in the circuit one can use chopper method to increase the average voltage applied, by the formula V/(1-α).

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Category: Electronics & Electrical MCQs
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74
Q:

How output voltage of chopper can be varied?

A) By using constant frequency system B) By using variable frequency system
C) By using constant and variable frequency systems D) By using constant or variable frequency systems
 
Answer & Explanation Answer: C) By using constant and variable frequency systems

Explanation: The average voltage of the chopper output depends on α, thus, α can be varied by either changing the complete time period or by changing an on time or off time. These two methods are named as constant and variable frequency system.

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Category: Electronics & Electrical MCQs
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52
Q:

The average value of chopper output waveform is given by _____________

A) αV B) V/α
C) α2V D) V/α2
 
Answer & Explanation Answer: A) αV

Explanation: Here the average value of the chopper output voltage waveform is given by Va=V tON/(tON+tOFF) = V (tON/T) =αV. So, by varying duty cycle α one can vary the average voltage at output.

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Category: Electronics & Electrical MCQs
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93
Q:

Which of the following correctly suits with chopper?

A) Thyristor in series with load B) Thyristor in parallel with load
C) Thyristor switch in series with load D) Thyristor switch in parallel with load
 
Answer & Explanation Answer: C) Thyristor switch in series with load

Explanation: A chopper is essentially a thyristor switch in series with the load. A shunting diode is provided across the load because free-wheeling the load current when thyristor is off. The thyristor can be shown enclosed by a dotted square can be turned-off over a time period and the cycle is repeated.

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Category: Electronics & Electrical MCQs
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134
Q:

Which of the following statement is not true regarding to DC chopper?

A) Cheap B) Fast response
C) Regeneration D) AC to DC control
 
Answer & Explanation Answer: D) AC to DC control

Explanation: The chopper provides stepless and efficient control of DC voltage and it is less expensive. It is having another advantage of faster response and regeneration. The chopper is relatively new technology and equivalent to DC-DC transformer.

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