The standard meter was defined by Michelson using light emitted from:
Correct answer: B. Cadmium
- A. Cesium
- B. Cadmium
- C. Platinum
- D. Gold
Explanation
The correct option is B because The standard meter was originally defined in terms of the wavelength of a particular spectral line of cadmium, specifically the red cadmium line at 6438.4696 angstroms. This definition was later replaced by the definition based on the speed of light.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Optics
Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
Practise Optics
665 free Optics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 11 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Optics questions
Bending of light around the edges of obstacles is called:
Which cannot be polarized?
Light from the Sun reaches the Earth in the form of:
In Newton's rings, the central spot for transmitted rays will appear:
If the movable mirror in an interferometer is moved through 2 wavelengths, the number of fringes observed is:
A fringe is a locus of: