Like the solar spectrum the spectra of stars show a continuous spectrum on which dark absorption lines are superimposed. The inner layer (called the photosphere) of the star emits radiations of all wavelengths, producing a continuous spectrum. When these radiations pass through the outer, relatively cooler, layer of the star, the radiations of certain wavelengths are selectively absorbed by this layer. This explains the dark lines in the spectrum of a star. The dark lines are characteristic of the substances present in the outer layer of the star. The surface temperature T of a star can be estimated by measuring the wavelengths λm at which the intensity of the emitted radiation is maximum and then using Wien's displacement law which states that λm x T = b where b is a constant called Wien's constant and the above relation is called Wien's Displacement Law which states that as the temperature increases, the maximum intensity of emission shifts (or is displaced) towards the shorter wavelengths. The value of constant b has been found experimentally to be 2.89 x 10−3mK .
Wiens displacement law tells us that an extremely hot star should look :
Like the solar spectrum the spectra of stars show a continuous spectrum on which dark absorption lines are superimposed. The inner layer (called the photosphere) of the star emits radiations of all wavelengths, producing a continuous spectrum. When these radiations pass through the outer, relatively cooler, layer of the star, the radiations of certain wavelengths are selectively absorbed by this layer. This explains the dark lines in the spectrum of a star. The dark lines are characteristic of the substances present in the outer layer of the star. The surface temperature T of a star can be estimated by measuring the wavelengths λm at which the intensity of the emitted radiation is maximum and then using Wien's displacement law which states that λm x T = b where b is a constant called Wien's constant and the above relation is called Wien's Displacement Law which states that as the temperature increases, the maximum intensity of emission shifts (or is displaced) towards the shorter wavelengths. The value of constant b has been found experimentally to be 2.89 x 10−3mK .
Wiens displacement law tells us that an extremely hot star should look :
The correct option is B violet or indigo
From wein's displacement law λmaxT=constant
So we can say that from this relation that if temperature of body increases then wavelength will decreases.
from the newton prism when white light passes through a prism it comes out in seven different colour of different wavelength.
So increasing order of wavelength and decreasing order of temperature are as follow :
violet<indigo<blue<green<yellow<orange<red
Hence, hot star which have very high temperature should look like violet or indigo.
From wein's displacement law λmaxT=constant
So we can say that from this relation that if temperature of body increases then wavelength will decreases.
from the newton prism when white light passes through a prism it comes out in seven different colour of different wavelength.
So increasing order of wavelength and decreasing order of temperature are as follow :
violet<indigo<blue<green<yellow<orange<red
Hence, hot star which have very high temperature should look like violet or indigo.
