The wavelength of X-rays is of the order of

A. 10 micron
B. 1 angstrom
C. 1 सेमी
D. 1 मीटर


Mesons are found in

A. Laser beam
B. एक्स-रे
C. गामा किरणें
D. कॉस्मिक किरणों


Which radioactive pollutant has recently drawn to public, due to its occurrence in the building material?

A. Thorium
B. रेडियम
C. प्लूटोनियम
D. Radan


Which of the following shows the masses of the three elementary particles in decreasing order?

A. Leptons, Baryons, Mesons
B. Mesons, बेरियान कणिकाओं, leptons
C. बेरियान कणिकाओं, mesons, leptons
D. Leptons, mesons बेरियान कणिकाओं


What is the wavelength of visible spectrum?

A. 8500 - 9800 angstrom
B. 7800 - 8000 angstrom
C. 3900 - 7600 angstrom
D. 1300 - 3000 angstrom