Question

The number of photons of frequency 10ka power 14 Hz in radiation of 6.62j will be-

Answer 1

we know,
$\bold{energy \: of \: one \: photon = h\nu}$
where h is Plank's constant and v is the frequency of incident radiation .

given,
h = 6.62 × 10⁻³⁴ Js
v = 10¹⁴ Hz
so, Energy of one photon = 6.62 × 10⁻³⁴ × 10¹⁴
energy of one photon = 6.62 × 10⁻²⁰ J

now use formula,
$\bold{\text{number of photons} = \frac{\text{given energy}}{\text{energy of one photon}}}$

given energy = 6.62 J
so, number of photons = 6.62J/6.62 × 10⁻²⁰
number of photons = 10²⁰

Answer 2

Energy Of Photon E=hν
Where h is Planck's constant =6.626176 x 10⁻³⁴ Js
ν is frequency of radiation.=10¹⁴Hz
Energy E=6.62 x10⁻³⁴x10¹⁴
=6.62 x 10⁻²⁰ J

Number of photons = Overall Given energy/ Energy of single photon.
=6.6 2J/6.62 x 10⁻²⁰
=10²⁰
∴The number of photons of frequency 10¹⁴ Hz in radiation of 6.62j will be 10²⁰.