Radiant Energy Formula


Radiant Energy Formula

The Radiant heat energy is a notion which is rather more nicely explained by Stefan’s law. This law elucidates how the heat is radiated! It states that, The amount of heat which is radiated (E) by a flawless black body for a second in a provided unit area is directly related to the fourth power of its absolute temperature (T).

The Radiant heat energy formula is articulated as,

α T4


E = σ T4

Stefan’s constant (5.67 × 10−8−8 W/m2/K4) is σ ,

radiant energy is E,

absolute temperature is T.

Radiant Energy Solved Problems

Some of the solved numerical based on Radiant Energy is provided underneath:

Problem 1: The surface temperature of the moon in the daytime is 123 Celsius. Compute the radiant heat energy for 1meter square area.

Known: T (Temperature) = 123 C = 123 + 273 K = 396 K

σ (Stefans Constant) = 5.67 × 10−8−8 W/m22/K44

Radiant energy, E = σ T44

E = 5.67 × 10−8−8 W/m2/K4 × (396)4

E = 1394.32.

Thus, the radiant heat energy is 1394.32. 

Problem 2: If the radiant energy of the body is 129.34, calculate its surface temperature.



E (Radiant energy) = 129.34,

σ (Stefans Constant)  = 5.67 × 10^-8 W/m2/K4

Radiant energy, E = σ T4

Thus, the temperature of the surface is 218.54 K.



Practise This Question

What are the factors for which crop improvement is desirable?

i. Higher yield
ii. Improved quality
iii. Good looks
iv. Disease resistance
v. More height
vi. Wider adaptability