Question

What is the physical meaning of taking $d\ll \lambda$?

Answer 1

Hey dear here is the answer


The Greek letter "L," which is used as a symbol for "wavelength." A lambda is a particular frequency of light, and the term is widely used in optical networking. ... See WDM and wavelength. Lambda. The symbol above the word "wavelength" in this diagram is the Greek Lambda.


Hope its help you

Answer 2

Answer:

I'm studying electromagnetic radiation from Jackson's book, but I have a question. I understand that electromagnetic radiation is the flux of electromagnetic energy to infinity, according with Griffiths' definition, but I have a problem; When Jackson (Third Edition 1999, page 408) consider a localized oscillating source and calculate the vector potential A, he takes the limit d≪λ, where d is the characteristic dimension of the source and λ is the characteristic wavelength of the fields.