Electrical Engineering (EE) Exam  >  Electrical Engineering (EE) Questions  >  The luminous efficiency of a sodium vapour la... Start Learning for Free
The luminous efficiency of a sodium vapour lamp is:
  • a)
    40-50 lumens/W
  • b)
    50-100 lumens/W
  • c)
    120-200 lumens/W
  • d)
    10-12 lumens/W
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)5...
Ratings of normal sodium vapour lamp:
1) The efficiency of sodium vapour lamp is lies between 40 and 50 lumens/W
2) Normally these lamps are manufactured in 45 W, 60 W, 85 W and 140 W ratings
3) The normal operating temperatures of these lamps are 300° C
4) The average value life of the sodium vapour lamp is 3000 hr and these are not affected by voltage variations
View all questions of this test
Most Upvoted Answer
The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)5...
Luminous Efficiency of Sodium Vapour Lamp

Luminous efficiency is the ratio of the luminous flux emitted by a light source to the power consumed by the source. Sodium vapour lamps are a type of high-intensity discharge (HID) lamps that produce light by the excitation of sodium vapour.

The luminous efficiency of a sodium vapour lamp is given as:

a) 40-50 lumens/W

This means that for every watt of power consumed by the lamp, it produces around 40-50 lumens of light.

Factors Affecting Luminous Efficiency

The luminous efficiency of a lamp depends on various factors such as:

1. Lamp Type: Different types of lamps have different luminous efficiencies. For example, LED lamps have higher luminous efficiencies than incandescent lamps.

2. Lamp Design: The design of the lamp also affects its luminous efficiency. For example, lamps with better reflectors or lenses can direct more light towards the desired area, resulting in higher luminous efficiency.

3. Operating Conditions: The operating conditions of the lamp, such as the temperature and voltage, can affect its luminous efficiency. In general, lamps operate at their maximum efficiency when they are operated at their rated voltage and temperature.

Advantages of Sodium Vapour Lamps

Sodium vapour lamps have several advantages over other types of lamps, such as:

1. Energy Efficiency: Sodium vapour lamps are more energy-efficient than incandescent lamps and some other types of HID lamps.

2. Long Life: Sodium vapour lamps have a longer lifespan compared to other types of lamps.

3. High Luminous Efficacy: Sodium vapour lamps have a high luminous efficacy, meaning they produce more light per watt of power consumed.

4. Good Color Rendering: Sodium vapour lamps have good color rendering properties, making them suitable for outdoor lighting applications.

Conclusion

The luminous efficiency of a sodium vapour lamp is around 40-50 lumens per watt. This makes them an energy-efficient lighting option with a long lifespan and good color rendering properties.
Free Test
Community Answer
The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)5...
The efficiency of a sodium vapour lamp under practical conditions is about 40-50 lumens/watt. Such lamps are manufactured in 45, 60, 85 and 140 W ratings. The average life is about 3000 hours and is not affected by voltage variations
Explore Courses for Electrical Engineering (EE) exam

Top Courses for Electrical Engineering (EE)

The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer?
Question Description
The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer?.
Solutions for The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Electrical Engineering (EE). Download more important topics, notes, lectures and mock test series for Electrical Engineering (EE) Exam by signing up for free.
Here you can find the meaning of The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice The luminous efficiency of a sodium vapour lamp is:a)40-50 lumens/Wb)50-100 lumens/Wc)120-200 lumens/Wd)10-12 lumens/WCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Electrical Engineering (EE) tests.
Explore Courses for Electrical Engineering (EE) exam

Top Courses for Electrical Engineering (EE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev