On observing light from three different stars P, Q and R. It was found that intensity of violet colour is maximum in the spectrum of P, the intensity of green colour is maximum in the spectrum of R and the intensity of red colour is maximum in the spectrum of Q. If are the respective absolute temperature of P, Q and R, then it can be concluded from the above observations that
From Wein's displacement law,
R-max. intensity is at given
Q-max intensity is at red is maximum
i.e.,