If 5% of the energy supplied to a bulb is irradiated as visible light, how many quanta are emitted per second by a 100 W lamp? (Assume, wavelength of
If 5% of the energy supplied to a bulb is irradiated as visible light, how many quanta are emitted per second by a 100 W lamp? (Assume, wavelength of visible light as `5.6xx10^(-5)cm`)
A. `1.4xx10^(19)`
B. `3xx10^(3)`
C. `1.4xx10^(-19)`
D. `3xx10^(4)`
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Correct Answer - A
Energy radiated as visible light `=(5)/(100)xx100=5Js^(-1)`
Let n be the number of photons emitted per second.
then, `nhv=E=5`
`thereforen=(5lamda)/(hc)=(5xx5.6xx10^(-7))/((6.62x10^(-34))(3xx10^(8)))=1.4xx10^(19)`
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