Question

The number of photons of light of frequency 10 s-1 equivalent to 1 J is​

Answer 1

Answer:

Energy = n × hc/λ

n = Energy × λ / (hc)

= 1 J × 7000 × 10^-10 m / (6.626 × 10^-34 J s × 3 × 10^8 m/s)

= 3.5 × 10^18 photons

= 3.5 Quintillion photons

Number of photons = 3.5 Quintillion

4.4

Answer 2

Given:

The frequency of photons, ν = 10 s⁻¹

The total energy, T.E = 1 J

To Find:

The no of photons equivalent to 1 joule.

Calculation:

The energy of 1 photon, E = hν

⇒ E = 6.63 × 10⁻³⁴ × 10

⇒ E = 6.63 × 10⁻³³ J

- No of photons, n = Total energy / Energy of 1 photon

n = 1 / 6.63 × 10⁻³³

⇒ n = 15.083 × 10³¹

- So, the no of photons equivalent to 1 joule is 15.083 × 10³¹.