Comparing Energy Emissions: Microwave Ovens vs. Cell Phones

[jslag]

If the EM waves emitted by a cell phone and a microwave oven have similar frequencies, what does it mean that the waves emitted by the oven contain more energy? I believe that a microwave oven generates about 500 watts, whereas a cell phone generates only about 2 watts. What exactly does that mean? Since the wave frequencies are similar, does this mean that the oven produces waves with greater amplitude? I understand that the waves generated by the oven are amplified inside the oven itself, but I'm trying to understand what makes the waves themselves different to begin with.

 

[Averagesupernova]

The method in which they are generated are different. A microwave oven uses something called a magnetron. It is a type of vacuum tube and uses resonant cavities to set up electromagnetic oscillations. A cell phone uses transistors as oscillators and amplifiers to do the same thing much more precisely controlled and at a much lower power level. As you stated in your first post, the oven generates waves with greater amplitude.

 

[interested_learner]

Huh? What am I missing here? The amount of energy carried by a photon is related to its frequency. The difference between the two items is in the number of photons emitted. Other than that, a photon is a photon and if the frequencies are the same, the energy carried is the same (per photon).

 

[Gokul43201]

Huh? What am I missing here? The amount of energy carried by a photon is related to its frequency. The difference between the two items is in the number of photons emitted. Other than that, a photon is a photon and if the frequencies are the same, the energy carried is the same (per photon).

The OP was looking at it from the classical/wave point of view, where the energy density is proportional to the square of the amplitude of the wave. In the quantum picture, your description is correct - the microwave emits more photons per second per unit solid angle than the cellphone.