Use the formula λmT = 0.29 cm K to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. What do the numbers that you obtain tell you?

According to the planck’s law of radiation:

λm T = 0.29 cm K


or λm = 0.29/T cm K


where T is the temperature and λm is the maximum wavelength of the wave


for different values of maximum wavelengths such as λm = 10-4 cm, 5 × 10-5 cm and 10-6 cm, the values for temperatures can be calculated as follows:


T = 0.29/λm cm K


When, λm = 10-4 cm


T = 0.29/10-4 cm K


T = 2900 K


When, λm = 5× 10-5 cm


T = cm K


T = 5800 K


When, λm = 10-6 cm


T = 0.29/10-6 cm K


T = 290000 K


The above data shows that temperature is required to get radiations of different parts of electromagnetic spectrum and the temperature increases with decrease in the wavelength.


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