Question

When you hold up a piece of white notebook paper in sunlight, what color does the paper appear? Explain with reference to the thermal spectrum of the Sun A very hot star may have a temperature of 25.000 K. What is the peak wavelength of the spectrum of this star, and what kind of light is this? Does this very hot star emit light at wavelengths other than the peak wavelength? Explain with reference to its thermal spectrum What color would this hot star appear to the human eye? Explain based on the spectrum. A fellow student states the following: mars. We cannot see stars that hotin A really hot star like this will peak in ultraviolet liglet, wisice is imisible to the night sky w ithey are there! Do you agree or disagree with that conclusion? Explain.

Answer 1

I since . sun peak ware length is in Une visible wavelenath avelength [2 = 5000 [Am = 500nn] and it enits I all the 4 clows it appears wlule to human eye s a papei paper apped appeas white: Given T = 25,000 K Then from Wen's wein's displacement dans ais ay = b b.2-9 911 mm may = 2-6911870 25000 am = 1150 am = 115 mm This lies in the proced i ena Ultraviolet region.' 1 3 The star emit at other wavelength also. But the peak is at 115 m. The Black body radiction graph explains this.. Intensitish Scanned with CamScanner

4) The star will appear as bluish white since most of the intensity lies in the blue violet u region. The spectrum lies from uor light to visible region. 5 . Since the peak is in u-v region. It doen it mean the star is not emitting light in othes Warelength. A band of spectrum is for a stal and it emits light of frequencies at various frequencies. we can see stars like sirius which are very hot stars as bluish white since it radiate in the visible region ayo. Scanned with CamScanner