Question
Download Solution PDFTwo electric lamps have filaments of the same metal having the same thickness. If one of them gives 100 watt and other gives 500 watt across the same supply, then:
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept
When two lamps are connected in parallel (same supply), the power of each lamp is given by:
\(P={V^2\over R}\)
The resistance is given by:
\(R={ρ l\over A}\)
where, ρ = Resistivity
l = Length
A = Area
Calculation
\(P={V^2A\over \rho l}\)
From the above expression, for the same metal having the same thickness, the power is inversely proportional to length.
Hence, a 100-watt lamp filament has a longer length than a 500-watt lamp.
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.