A bulb emits light of wavelength 4500 Å. The bulb is rated as 150 watt and 8% of the energy is emitted as light. How many photons are emitted by the bulb per second ?

A bulb emits light of wavelength 4500 Å. The bulb is rated as 150 wat

1.	A bulb emits light of wavelength 4500 Å. The bulb is rated as 150 watt and 8% of the energy is emitted as light. How many photons are emitted by the bulb per second ?
Answer» <html><body><p></p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/electrical-968148" style="font-weight:bold;" target="_blank" title="Click to know more about ELECTRICAL">ELECTRICAL</a> energy in joules = Power in watts `xx` Time in seconds <br/> <a href="https://interviewquestions.tuteehub.com/tag/thus-2307358" style="font-weight:bold;" target="_blank" title="Click to know more about THUS">THUS</a> <a href="https://interviewquestions.tuteehub.com/tag/150-275254" style="font-weight:bold;" target="_blank" title="Click to know more about 150">150</a> watt = 150 joules of energy emitted per second <br/> `:.` Energy emitted as light `= (8)/(100) xx 150 = 12J` <br/> `E = n <a href="https://interviewquestions.tuteehub.com/tag/hv-1033771" style="font-weight:bold;" target="_blank" title="Click to know more about HV">HV</a> = nh (c)/(lamda) " " :. n = (E xx lamda)/(h xx c) = ((12J) xx (4500 xx 10^(-10) m))/((6.626 xx 10^(-34) Js) xx (3 xx 10^(8) ms^(-1))) = 2.717 xx 10^(19)`</body></html>