A light emitting diode produces light of wavelength 850 nm. When you turn it on and look at it you see:Select one:a.Nothing as 850 nm is ultraviolet (UV) radiation.b.Green Light c.Blue Light d.Nothing as 850 nm is infrared (IR) radiation.e.Red Light

The approximate wavelength of Red light isa.3000Ǻb.7000Ǻc.3500Ǻd.100

A light emitting diode produces light when:Select one:a.an electron undergoes a transition from the valence band to the conduction band.b.an electron decreases its energy when in the valence band.c.an electron undergoes a transition from the conduction band to the valence band.d.an electron increases its energy when in the conduction band.

Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per second on the average at a target irradiated by this beam is :

The portion of colored light within the electromagnetic spectrum that is visible to the human eye.Group of answer choicesWavelengthVisible SpectrunFull spectrum lightNone of the above

The threshold wavelength for photoelectric emission from a material is 5500 A∘. Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from aA. 75 W infra-red lampB. 10 W infra-red lampC. 75 W ultra-violet lampD. 10 W ultra-violet lampChoose the correct answer from the options given below :B and C onlyA and D onlyC onlyC and D only