Two stars emit maximum radiation at wavelength 360 mm and 480 mm respectively. The ratio of their temperature is

Concept:

• Wien's displacement law: This law says that the spectral radiance of a black-body radiation per unit wavelength, has different peaks of temperature at wavelengths and given by:

\(λ_{peak}=\frac{b}{T}\)

where T is the temperature in Kelvin and b is a Wien's displacement constant, equal to 2.89 × 10−3 m⋅K​

• For two different temperatures, T1 and T2 max energy wavelengths are λ1 and λ2, then by Wien's displacement law

\(\frac{T_1}{T_2}=\frac{λ_2}{λ_1}\)

CALCULATION:

Given that λ1 = 360 mm and λ2 = 480 mm

By Wien's displacement law

\(\frac{T_1}{T_2}=\frac{λ_2}{λ_1}\)

\(\frac{T_1}{T_2}=\frac{480}{360}=\frac{4}{3}\)

So the correct answer is option3.