Before we start calculating the number of photons emitted by a 60 watt bulb in 10 hours, let us first understand the basic concepts involved in the question.


A photon is an elementary particle that is the quantum of the electromagnetic field, including electromagnetic radiation such as light. Photons are massless, have no electric charge, and always move at the speed of light.


The frequency of light is the number of waves that pass a point in space in one second. The unit of frequency is Hertz (Hz). The frequency of light is directly proportional to its energy.


We can use the following formula to calculate the number of photons emitted by a 60 watt bulb in 10 hours:

Number of photons = (Power x Time)/(Energy per photon)

Where,
Power = 60 watts (Given)
Time = 10 hours (Given)
Energy per photon = Planck's constant x frequency of light

Planck's constant = 6.626 x 10^-34 Joule-second
Frequency of light = Speed of light/wavelength of light

Speed of light = 3 x 10^8 m/s
Wavelength of light = 550 nm (Approximate wavelength of yellow light emitted by a bulb)

Frequency of light = Speed of light/wavelength of light = (3 x 10^8)/(550 x 10^-9) Hz = 5.45 x 10^14 Hz

Energy per photon = Planck's constant x frequency of light = (6.626 x 10^-34) x (5.45 x 10^14) = 3.61 x 10^-19 Joule

Number of photons = (Power x Time)/(Energy per photon) = (60 x 10 x 3600)/(3.61 x 10^-19) = 6.01 x 10^24 photons

Therefore, the number of photons emitted by a 60 watt bulb in 10 hours is 6.01 x 10^24.


In conclusion, we can say that the number of photons emitted by a 60 watt bulb in 10 hours is a very large number. This calculation helps us understand the quantum nature of light and the importance of Planck's constant in the calculation of energy per photon.