Which of the following types of stars is the coolest? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum.

Coolest star is corresponding to that graph which have maximum wavelength. so correct answer will be

In Graph A, the curve peaks at 800 nm, in the red section of the visible light spectrum.

Explanation:

As we know by Wein's Displacement law that

here it shows that

= wavelength corresponding to maximum intensity

T = temperature

so here if wavelength and temperature is inversely depends on each other so we can say if wavelength corresponding to maximum intensity is small then its temperature must be high.

In graph A wavelength is 800 nm

In graph B wavelength is 550 nm

In graph C wavelength is 450 nm

In graph D wavelength is 300 nm

so here coolest star must be corresponding to graph A

multiply 2kg by latent heat of vap