# What is the emissive power?

##### 1 Answer
Sep 12, 2016

The emissive power ${e}_{l} a m \mathrm{da}$ of a body for radiation of wavelength $l a m \mathrm{da}$ to $l a m \mathrm{da} + \mathrm{dl} a m \mathrm{da}$ is the amount of radiation emitted per unit area of the body per second normally in unit solid angle in the axial direction of the solid angle.