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,

E α T4


E = σ T4

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

Radiant energy is E

Absolute temperature is T

Solved Example

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

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

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

Radiant energy, E = σ T4

E = (5.67 × 10−8) × (396)4

E = 1394.32.

Thus, the radiant heat energy is 1394.32. 

Register to “BYJU’S – The Learning App” for loads of interactive, engaging Physics-related videos and an unlimited academic assist.


Leave a Comment

Your Mobile number and Email id will not be published.