Railways Exam > Railways Questions > A 400 V, three-phase, four-wire is feeding a...
Start Learning for Free
A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?
- a)0.43 A
- b)0.86 A
- c)4.61 A
- d)2.31 A
Correct answer is option 'A'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
A 400 V, three-phase, four-wire is feeding a balanced load of 100 W l...
During balance load total power P = 3 × 100 = 300 W
View all questions of this test
If the lamp in one of the phases goes off, then total power = 300 × 0.57 = 171 W
∴ the reading of ammeter connecting neutrals = 171/400 = 0.43 A
Most Upvoted Answer
A 400 V, three-phase, four-wire is feeding a balanced load of 100 W l...
Given information:
- Voltage: 400 V
- Three-phase, four-wire system
- Balanced load: 100 W lamp in each phase
To find: Reading of the ammeter connecting neutrals of the supply and load when one of the lamps goes off.
Explanation:
1. Balanced Load:
In a balanced load, the three phases are identical and draw equal power. Since each phase has a 100 W lamp, the total power consumed by the load is:
Total Power = Power per Phase x Number of Phases
Total Power = 100 W x 3 = 300 W
2. Neutral Current in Balanced Load:
In a balanced load, the neutral current is ideally zero. This is because the currents in the three phases cancel each other out in the neutral conductor.
3. Lamp Goes Off:
When one of the lamps goes off, the load becomes unbalanced. The two remaining lamps continue to draw power, but the faulty lamp consumes no power.
4. Unbalanced Load:
In an unbalanced load, the currents in the three phases are not equal, resulting in a non-zero neutral current.
5. Calculation:
Since the faulty lamp is not consuming any power, the total power consumed by the load reduces to:
Total Power = Power per Phase x Number of Remaining Phases
Total Power = 100 W x 2 = 200 W
To calculate the neutral current, we can use the formula:
Neutral Current = Total Power / Line-to-Neutral Voltage
Neutral Current = 200 W / 400 V
Neutral Current = 0.5 A
However, the question asks for the reading of the ammeter connecting neutrals of the supply and load. In a balanced load, the neutral current is ideally zero. When one of the lamps goes off, the load becomes unbalanced and a non-zero neutral current flows. Therefore, the reading of the ammeter will be 0.5 A, which is option A.
- Voltage: 400 V
- Three-phase, four-wire system
- Balanced load: 100 W lamp in each phase
To find: Reading of the ammeter connecting neutrals of the supply and load when one of the lamps goes off.
Explanation:
1. Balanced Load:
In a balanced load, the three phases are identical and draw equal power. Since each phase has a 100 W lamp, the total power consumed by the load is:
Total Power = Power per Phase x Number of Phases
Total Power = 100 W x 3 = 300 W
2. Neutral Current in Balanced Load:
In a balanced load, the neutral current is ideally zero. This is because the currents in the three phases cancel each other out in the neutral conductor.
3. Lamp Goes Off:
When one of the lamps goes off, the load becomes unbalanced. The two remaining lamps continue to draw power, but the faulty lamp consumes no power.
4. Unbalanced Load:
In an unbalanced load, the currents in the three phases are not equal, resulting in a non-zero neutral current.
5. Calculation:
Since the faulty lamp is not consuming any power, the total power consumed by the load reduces to:
Total Power = Power per Phase x Number of Remaining Phases
Total Power = 100 W x 2 = 200 W
To calculate the neutral current, we can use the formula:
Neutral Current = Total Power / Line-to-Neutral Voltage
Neutral Current = 200 W / 400 V
Neutral Current = 0.5 A
However, the question asks for the reading of the ammeter connecting neutrals of the supply and load. In a balanced load, the neutral current is ideally zero. When one of the lamps goes off, the load becomes unbalanced and a non-zero neutral current flows. Therefore, the reading of the ammeter will be 0.5 A, which is option A.
Attention Railways Students!
To make sure you are not studying endlessly, EduRev has designed Railways study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Railways.
|
Explore Courses for Railways exam
|
|
Top Courses for RailwaysView all
A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer?
Question Description
A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? for Railways 2024 is part of Railways preparation. The Question and answers have been prepared according to the Railways exam syllabus. Information about A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Railways 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer?.
A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? for Railways 2024 is part of Railways preparation. The Question and answers have been prepared according to the Railways exam syllabus. Information about A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Railways 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer?.
Solutions for A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Railways.
Download more important topics, notes, lectures and mock test series for Railways Exam by signing up for free.
Here you can find the meaning of A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer?, a detailed solution for A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A 400 V, three-phase, four-wire is feeding a balanced load of 100 W lamp in each phase. If the lamp in one of the phases goes off. What will be the reading of the ammeter connecting neutrals of the supply and load?a)0.43 Ab)0.86 Ac)4.61 Ad)2.31 ACorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Railways tests.
|
|
Explore Courses for Railways exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup