Irradiance of electromagnetic radiation from a point source of radiation decreases with distance from the source and obeys the inverse square law.
How is the irradiance of electromagnetic radiation defined?
The energy per second of the radiation per unit area
The total energy of radiation for each square metre
The area affected by the radiation divided by the power of the radiation
Which graph illustrates the relationship between irradiance from a point source and distance from the source?
The irradiance from a small lamp is 0.584 W m-2 at a distance 0.64 m from the lamp. What would be the expected irradiance at a distance 0.96 m from the lamp?
0.260 W m-2
0.389 W m-2
1.31 W m-2