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6% of the energy supplied to a 100 watt ...

6% of the energy supplied to a 100 watt lamp is radiated as visible light of wavelength 6620 Å. How many quanta are emiited per second ?

A

`10^(19)`

B

`2xx10^(19)`

C

`5xx10^(-19)`

D

`2xx10^(5)`

Text Solution

Verified by Experts

The correct Answer is:
B
Energy radiated as visible light `=(6)/(100)xx100=6`J/s
`E=nhv=(nhC)/(lambda)`
`:.n=(Elambda)/(hC)=(6xx6.62xx10^(-7))/(6.62xx10^(-34)xx3xx10^(8))=2xx10^(19)`
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MARVEL PUBLICATION-ELECTRONS AND PHOTONS -TEST YOUR GRASP - 17
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