Question

Calculate the number of photons in 6.62J of radiation energy of frequency 1012 Hz.

Answer 1

Question:

Calculate the number of photons in 6.62J of radiation energy of frequency 1012 Hz.

★ Answer

Energy = Nhṿ

where h = planks constant

N = no of photons

ṿ = frequency of radiation

therefore;

Energy = Nhṿ

$6.626 = n \times 6.63 \times 10 {}^{ - 34} \times 1012$

$n = \frac{6.626}{6.63 \times 10 {}^{ - 34} \times 1012 }$

on solving ;

$n = 0.99 \times 1012 \times 10 {}^{34}$

$= 1010.4 \times 10 {}^{34} photons$

Answer 2

Answer:

In a 6.62J of radiation energy of frequency 1012 Hz, there are

$9.8*10^{30}$ photons present

Explanation:

• According to the quantum theory of radiation, the photon energy is quantized

• For radiation of frequency (ν) the energy (E) is given as

       $E=nh$ν

       where,

       n-number of photons

       $h=6.6*10^{-34} Js$-Planck's constant

From the question, we have

the energy of the radiation $E=6.62J$

frequency of the radiation ν $=1012 Hz$

by rearranging the equation

number of photons in the radiation is

$n=E/h$ν

$n=\frac{6.62}{6.6*10^{-34}*1012}=9.8*10^{30}$