Which of the following lamps is well suited for street lightning in terms of high luminous efficiency?

This question was previously asked in
SSC JE Electrical 10 Oct 2023 Shift 2 Official Paper-I
View all SSC JE EE Papers >
  1. Fluorescent lamp
  2. Compact fluorescent lamp
  3. Incandescent lamp
  4. Sodium vapour lamp

Answer (Detailed Solution Below)

Option 4 : Sodium vapour lamp
Free
RRB JE CBT I Full Test - 23
14.2 K Users
100 Questions 100 Marks 90 Mins

Detailed Solution

Download Solution PDF

Luminous Efficiency of lamps:

Lamp

Lamp efficiency

Carbon filament lamp

3-5 lumen/watt

Incandescent lamp

8-40 lumen/watt

Neon lamp

15-40 lumen/watt

Fluorescent lamp

40-60 lumen/watt

Vacuum lamp 

30-40 lumen/watt

Gas-filled lamp

12 lumen/watt

Arc lamp

9-12 lumen/watt

Sodium vapor lamp

100-175 lumen/watt

 

  • Sodium vapor light lamps are most suitable for street lighting because they emit yellow light which is the easiest color to recognize in the night or darkness.
  • It can last up to 24,000 hours, which is about four times as long as mercury vapor lamps and 24 times as long as incandescent lamps.
  • It does not require frequent replacement or cleaning, which reduces labor and disposal costs.
  •  It can produce up to 150 lumens per watt, which is about twice as much as mercury vapor lamps and five times as much as incandescent lamps.

Additional Information

Application of different lamps: 

Types of Lamp

Application

Neon lamps

visual indicators in electronic equipment and appliances

Fluorescent lamps

commercial lighting, industrial lighting, classroom lighting,

Sodium vapor lamp

roadways, parking lots, security areas, airports, goods yards

Carbon arc lamp

cinema projector, searchlight, flash camera

Latest SSC JE EE Updates

Last updated on May 29, 2025

-> SSC JE Electrical 2025 Notification will be released on June 30 for the post of Junior Engineer Electrical/ Electrical & Mechanical.

-> Applicants can fill out the SSC JE application form 2025 for Electrical Engineering from June 30 to July 21.

-> SSC JE EE 2025 paper 1 exam will be conducted from October 27 to 31. 

-> Candidates with a degree/diploma in engineering are eligible for this post.

-> The selection process includes Paper I and Paper II online exams, followed by document verification.

-> Prepare for the exam using SSC JE EE Previous Year Papers.

Get Free Access Now
Hot Links: teen patti mastar teen patti real online teen patti real money teen patti party teen patti joy 51 bonus