If a source of power 4 kW produces 10^{20} photons/second , radiation belongs to a part of spectrum

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8.Electromagnetic waves

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If a source of power $4\ kW$ produces $10^{20}$ photons/second , the radiation belongs to a part of the spectrum called

A

$\;\gamma $ -rays

B

$X$-rays

C

Ultraviolet rays

D

Microwaves

(AIEEE-2010)

Solution

Power, $P=\frac{n h v}{t}$

$\Rightarrow v=\frac{P \times t}{n h}$

$=\frac{4 \times 10^{3} \times 1}{10^{20} \times 6.63 \times 10^{-34}}=6 \times 10^{16}\, \mathrm{Hz}$

Standard 12

Physics

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