Homework Help is Here – Start Your Trial Now!
Engineering
Mechanical Engineering
An incandescent light bulb is an inexpensive but highly inefficient device that converts electrical energy into light. It converts about 10 percent of the electrical energy it consumes into light while converting the remaining 90 percent into heat. (A fluorescent light bulb will give the same amount of light while consuming only one-fourth of the electrical energy, and it will last 10 times longer than an incandescent light bulb.) The glass bulb of the lamp heats up very quickly as a result of absorbing all that heat and dissipating it to the surroundings by convection and radiation. Consider a 0.525-m-diameter 100-W light bulb cooled by a fan that blows air at 30°C to the bulb at a velocity of 306 m/s. The surrounding surfaces are also at 30°C, and the emissivity of the glass is 0.9. Assuming 10 percent of the energy passes through the glass bulb as light with negligible absorption and the rest of the energy is absorbed and dissipated by the bulb itself, determine the equilibrium temperature of the glass bulb. Assume a surface temperature of 100°C for evaluation of µs- The properties of air at 1 atm pressure and the free stream temperature of 30°C are k = 0.02588 W/m°C, v = 1.608x1o-5 m²/s, µoo = 1.872x10-5 kg/m.s, Hs at 100°C = 2.181x10-5 kg/m.s, and Pr = 0.7282. 100 W 3 = 0.9* Light, 10 W

An incandescent light bulb is an inexpensive but highly inefficient device that converts electrical energy into light. It converts about 10 percent of the electrical energy it consumes into light while converting the remaining 90 percent into heat. (A fluorescent light bulb will give the same amount of light while consuming only one-fourth of the electrical energy, and it will last 10 times longer than an incandescent light bulb.) The glass bulb of the lamp heats up very quickly as a result of absorbing all that heat and dissipating it to the surroundings by convection and radiation. Consider a 0.525-m-diameter 100-W light bulb cooled by a fan that blows air at 30°C to the bulb at a velocity of 306 m/s. The surrounding surfaces are also at 30°C, and the emissivity of the glass is 0.9. Assuming 10 percent of the energy passes through the glass bulb as light with negligible absorption and the rest of the energy is absorbed and dissipated by the bulb itself, determine the equilibrium temperature of the glass bulb. Assume a surface temperature of 100°C for evaluation of µs- The properties of air at 1 atm pressure and the free stream temperature of 30°C are k = 0.02588 W/m°C, v = 1.608x1o-5 m²/s, µoo = 1.872x10-5 kg/m.s, Hs at 100°C = 2.181x10-5 kg/m.s, and Pr = 0.7282. 100 W 3 = 0.9* Light, 10 W

Elements Of Electromagnetics
Elements Of Electromagnetics
7th Edition
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Sadiku, Matthew N. O.
ChapterMA: Math Assessment
Section: Chapter Questions
Problem 1.1MA
See similar textbooks
icon
Related questions
Question
An incandescent light bulb is an inexpensive but highly inefficient device that converts electrical energy into light. It converts about 10 percent of the electrical energy it consumes into light while converting the remaining 90 percent into heat. (A fluorescent light bulb will give the same amount of light while consuming only one-fourth of the electrical energy, and it will last 10 times longer than an incandescent light bulb.) The glass bulb of the lamp heats up very quickly as a result of absorbing all that heat and dissipating it to the surroundings by convection and radiation. Consider a 0.525-m-diameter 100-W light bulb cooled by a fan that blows air at 30°C to the bulb at a velocity of 306 m/s. The surrounding surfaces are also at 30°C, and the emissivity of the glass is 0.9. Assuming 10 percent of the energy passes through the glass bulb as light with negligible absorption and the rest of the energy is absorbed and dissipated by the bulb itself, determine the equilibrium temperature of the glass bulb. Assume a surface temperature of 100°C for evaluation of us- The properties of air at 1 atm pressure and the free stream temperature of 30°C are k = 0.02588 W/m°C, v = 1.608x10-5 m2/s, Hoo = 1.872x10-5 kg/m.s, Hs at 100°C = 2.181x10-5 kg/m.s, and Pr = 0.7282. ww 100 W 2 = 0.9 Light, 10 W
Transcribed Image Text:An incandescent light bulb is an inexpensive but highly inefficient device that converts electrical energy into light. It converts about 10 percent of the electrical energy it consumes into light while converting the remaining 90 percent into heat. (A fluorescent light bulb will give the same amount of light while consuming only one-fourth of the electrical energy, and it will last 10 times longer than an incandescent light bulb.) The glass bulb of the lamp heats up very quickly as a result of absorbing all that heat and dissipating it to the surroundings by convection and radiation. Consider a 0.525-m-diameter 100-W light bulb cooled by a fan that blows air at 30°C to the bulb at a velocity of 306 m/s. The surrounding surfaces are also at 30°C, and the emissivity of the glass is 0.9. Assuming 10 percent of the energy passes through the glass bulb as light with negligible absorption and the rest of the energy is absorbed and dissipated by the bulb itself, determine the equilibrium temperature of the glass bulb. Assume a surface temperature of 100°C for evaluation of us- The properties of air at 1 atm pressure and the free stream temperature of 30°C are k = 0.02588 W/m°C, v = 1.608x10-5 m2/s, Hoo = 1.872x10-5 kg/m.s, Hs at 100°C = 2.181x10-5 kg/m.s, and Pr = 0.7282. ww 100 W 2 = 0.9 Light, 10 W
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Convection
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Elements Of Electromagnetics
Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press
Mechanics of Materials (10th Edition)
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON
Thermodynamics: An Engineering Approach
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education
Control Systems Engineering
Control Systems Engineering
Mechanical Engineering
ISBN:
9781118170519
Author:
Norman S. Nise
Publisher:
WILEY
Mechanics of Materials (MindTap Course List)
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:
9781337093347
Author:
Barry J. Goodno, James M. Gere
Publisher:
Cengage Learning
Engineering Mechanics: Statics
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:
9781118807330
Author:
James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:
WILEY
SEE MORE TEXTBOOKS