Q. Oil floating on water looks coloured due to interference of light. What should be the order of magnitude of thickness of oil layer in order that this effect may be observed?
A) $10,000\ \mathring{\mathrm{A}}$
B) $1\ cm$
C) $10\ \mathring{\mathrm{A}}$
D) $100\ \mathring{\mathrm{A}}$
Explanation
(a) Oil floating on water looks coloured only when thickness of oil layer=wavelength of light=$10000\mathring{\mathrm{A}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.