Question
Download Solution PDFA 200 V lamp has a total flux of 1000 lumens and takes a current of 0.5 A. Calculate its luminous efficiency?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFThe correct answer is option 3):(10 lumens/watt)
Concept:
Luminous efficiency:
It is defined as the ratio of the total luminous flux emitting from the source to its electrical power input in watts.
Lamp efficiency = luminous flux/power input
It is expressed in lumen/watt.
Calculation:
Given
Luminous flux = 1000 lumens,
V = 200 volts,
I = 0.5 A
Power input = 200 x 0.5 = 100 W
Luminous efficiency = 1000 / 100
Luminous efficiency = 10 lumens per watt
Last updated on Jun 16, 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.