Question

Temperature of surface of a body is 1227°C. Find out
the wavelength that body can radiate max energy. b =
0.289 cm-K.
​

Answer 1

Given:

The temperature of the body(T) = 1227°C

b = 0.289cm.K

To Find:

The wavelength of that body can radiate max energy.

Solution:

The temperature of the human body is 37°C. The intensity of radiation emitted by the human body is maximum at a wavelength that can be found by using Wien's displacement law.

T = 1227°C

T = (1227 + 273) According to Wien's law the λm is constant where λm is wavelength corresponding to the max intensity of radiation and T is the temperature of the body in Kelvin.

So, T = 1227 + 273 = 1500K

T = 1227+1000+273 = 2500K

λm = 5000Α

Now, λm/λm' = T/T'

= 1500/2500×5000

= 3000Α

Therefore, the wavelength that the body can radiate max energy is 3000Α.

Answer 2

Given:

Temperature of body = 1227°C

b = 0.289 cmK

To find:

The wavelength that body can radiate max energy

Explanation:

Temperature of body in kelvin = 1227° + 273

                                                     =1500 k

b = 0.289 cm K

Wien's displacement law =

                           T ∝ 1/λ

                           T = b/λ

                           λ = b/T = 0.2898/1500

                                       = 1.9 × 10⁻⁴ cm

length of wavelength = 1.9 × 10⁻⁴ cm

Answer =  1.9 × 10⁻⁴ cm