Question

Microwave ovens work by irradiating food with microwaves, which are absorbed by the water molecules in the food and converted to heat. Assuming that microwave ovens emit radiation with a wavelength of 14.8 cm, calculate how many photons are emitted per second in a 1 x 103-Watt microwave oven? (1 W = 1 J/s)

Answer 1

`7.45* 10^(26)` photons are emitted per second in a
`1* 10^3` Watt microwave oven.

Step-by-step explanation:

The expression for the power is:-

`Power=(Energy)/(Time)`

Also,
`E=n* (h* c)/(\lambda)`

Where,

n = the number of photons

h = Plank's constant having value
`6.626* 10^(-34)\ Js`

c = the speed of light having value
`3* 10^8\ m/s`

`\lambda` = the wavelength of the light

So,

`Power=(n)/(Time)* (h* c)/(\lambda)`

Thus, the expression for photons per second is:-

`(n)/(Time)=(Power* \lambda)/(h* c)`

Given that:-

Power = 10³ Watt

( 1 cm = 0.01 m)

[/tex]

So,

`Photon/sec=(10^(3)* 0.148)/(6.626* 10^(-34)* 3* 10^8)=7.45* 10^(26)`

`7.45* 10^(26)` photons are emitted per second in a
`1* 10^3` Watt microwave oven.