Question

a radio antenna emits electromagnetic waves at a frequency of 100 mhz and intensity of what is the photon density

Answer 1

photon density = 1.0 ×
`10^(16)` photon/m³

Step-by-step explanation:

given data

frequency f = 100 mhz = 100 ×
`10^(6)` Hz

we consider here intensity I = 0.2 W/m²

solution

we take here plank constant is h i.e = 6.626 ×
`10^(-34)` s

and take energy density is E

so here

E × C = I

E =
`(I)/(C)` ................1

here C = 3 ×
`10^(8)` m/s

so photon density is

photon density =
`(I)/(C) * (1)/(f * h)` ...............2

photon density =
`(0.2)/(3 * 10^8) * (1)/(100 * 10^6 * 6.626 * 10^(-34) )`

photon density = 1.0 ×
`10^(16)` photon/m³