Arc Phenomenon MCQ Quiz in தமிழ் - Objective Question with Answer for Arc Phenomenon - இலவச PDF ஐப் பதிவிறக்கவும்
Last updated on Mar 20, 2025
Latest Arc Phenomenon MCQ Objective Questions
Top Arc Phenomenon MCQ Objective Questions
Arc Phenomenon Question 1:
Which of the following is NOT a method used for extinction of arc?
Answer (Detailed Solution Below)
Arc Phenomenon Question 1 Detailed Solution
Shortening the arc is NOT a method used for extinction of arc.
Methods for arc quenching of a circuit breaker
Current Zero Method:
- The Current Zero Method is different because it relies on the natural current zero crossing in AC circuits.
- In AC systems, current passes through zero twice per cycle. Circuit breakers designed for AC use this point to interrupt the arc with minimal energy.
- Unlike the other three methods, it does not involve modifying the arc physically but rather utilizing the natural characteristics of AC current.
Cooling the Arc Method:
- The arc is cooled using air, oil, or gas, reducing its temperature and increasing resistance, leading to extinction.
Lengthening the Arc Method:
- The arc path is extended to increase resistance, making it more difficult for current to sustain.
Splitting the Arc Method:
- The arc is broken into multiple small arcs using arc splitters, increasing resistance and aiding in extinction.
Arc Phenomenon Question 2:
A 150 MVA, 22 kV synchronous generator having reactance of
The generator is at no load and rated voltage when a three-phase short circuit fault occurs between the breaker and transformer. The ratio of momentary current to sustained short circuit current of breaker is -
Answer (Detailed Solution Below) 17.5 - 17.7
Arc Phenomenon Question 2 Detailed Solution
Momentary current
Sustained short circuit current
The ratio of momentary current to sustained short circuit current of breaker
Arc Phenomenon Question 3:
Sparking between the contacts of a circuit breaker can be reduced by inserting
Answer (Detailed Solution Below)
Arc Phenomenon Question 3 Detailed Solution
Sparking between the contacts of a circuit breaker can be reduced by inserting a capacitor in parallel with the contacts.
Arc Phenomenon Question 4:
A 50 Hz, 20 kV generator is connected to a power system. The system reactance and capacitance per phase are: 5 mH and 0.6 mF respectively. What is the maximum voltage across the contacts of the circuit breaker at an instant when it passes through zero
Answer (Detailed Solution Below)
Arc Phenomenon Question 4 Detailed Solution
Maximum value of restriking voltage
= 2 × peak value of the system voltage
Arc Phenomenon Question 5:
Which of the following represent V-I characteristics of arc in circuit breaker.
Answer (Detailed Solution Below)
Arc Phenomenon Question 5 Detailed Solution
For arc in circuit breaker
Where
A,B, C, D are constant and l is arc length.