05-01-2018, 04:32 PM
Photoelectric effect
*The phenomenon of emission of electrons from a metal surface coated by sodium or potassium when light rays falls on it is called
Ans : photoelectric effect.
*Photoelectric effect was proposed by
Ans : Henrich Hertz.
*Photoelectric effect was explained by
Ans : Albert Einstein.
*The law of photo electric effect was formulated by
Ans : Albert Einstein
*Albert Eienstein won the Nobel prize in 1921 for the scientific explanation of photo electric effect.
*Einstein explained the photo electric effect on the basis of quantum theory
*The phenomenon, photo electric effect cannot be explained on the basis of electro magnetic theory.
*The colour of sky in moon
Ans : Black
*When a red flower is observed through blue glass plate, it appears,as
Ans : Black
*Colour of green leaf in red light
Ans : Black
*Colour which is very sensitive to human eye
Ans : Yellow
*Colour which is used in danger signals
Ans : Red (Because it has longest wavelength)
*Colours used in scientific laboratory for indicating danger
Ans : Yellow
*The colour used in fog lamp of vehicles
Ans : Yellow Light
Quantum Theory
*Quantum theory was put forwarded by Max Planck.
*Quantum theory states that the light rays consist of small energy packets called quantum.
*According to quantum theory, quantum of , light is known as a photon.
*Phenomenon of emission of light from substances after the absorbtion of photons is called Photoluminescence.
Must Read
*Colour having minimum wavelength
Ans : Violet
* Colour having maximum wavelength
Ans : Red
*Colour having minimum frequency
Ans : Red
*Colour having maximum frequency
Ans : Violet
*Light that scatters most
Ans : Violet
*Light that scatters least
Ans : Red
*The colour which reflects all other colours
Ans : White
*The colour which absorbs all other colours
Ans : Black
*The colour which absorbs maximum heat
Ans : Black
*The colour which absorbs minimum heat
Ans : White
*The colour which appears on the upper portion of the rainbow
Ans : Red
*The colour which appears on the lowest portion of rainbow
Ans : Violet
