When electric lights are operated on low-frequency ac (say, 5 Hz),they flicker noticeably. Why?
To explain:
The reason why the flickering becomes noticeable when some low frequency ac is used to operate the electric lights
Answer to Problem 13Q
Solution:
It happens because of the burning out frequency of the lights come quite under the maximum observable limit for a human eye.
Explanation of Solution
An alternating current, keeps on changing its direction of flow from one side to another. Therefore in every cycle, the current becomes zero two times, i.e. the bulb will stop burning out in the cycle two times. Now suppose, the frequency of ac is n, it means, the bulb will stop burning out 2n times in a second.
Many studies say that maximum observable rate for a human eye is about 20-50 hz. So, when the frequency of ac is so reduced like 5 Hz, it means the bulb will stop burning out 10 times in a second, i.e. the frequency of bulb being on and off being 10 Hz, which is quite under the maximum observable limit for a human eye. Hence, in low-frequency ac (say, 5 Hz), the electric lights flicker noticeably.
Chapter 18 Solutions
Physics: Principles with Applications
Additional Science Textbook Solutions
Applied Physics (11th Edition)
Life in the Universe (4th Edition)
Essential University Physics: Volume 2 (3rd Edition)
The Cosmic Perspective
Physics (5th Edition)
Conceptual Physics (12th Edition)
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON