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If 5% of the energy supplied to a bulb i...

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

`1.4 xx10^(19)`

B

`3 xx10^3`

C

`1.4 xx10^(-19)`

D

`3 xx10^4`

Text Solution

Verified by Experts

The correct Answer is:
A
Power radiated as visible light
`=100 xx5/100 = 5` J/sec
`n rarr` no. of photon emitted per second
P = nhn = 5
`implies n = (5lamda)/(hc) = (5xx5.6 xx10^(-7))/(6.6xx10^(-34)xx3xx10^8)=1.4 xx10^(19)`
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