7. Find the number of photons emitted per secondby a 25 watt source of

1.	7. Find the number of photons emitted per secondby a 25 watt source of monochromatic light ofwavelength 5000A°
Answer» 6000Å = 6000^-10m = 6.0^-7m From Planck's equation .. each photon has energy, E = hc/λ (J) If N photons are emitted per sec ..Total emission power, P = N(s⁻¹) x E(J) = NE (J/s) = 25 W 25 = NE = N x hc/λN = 25λ / hc .. 25 x 6.0^-7 / (6.625^-34 x 3.0^8) .. .. ►N = 7.55^19 photons per sec

7. Find the number of photons emitted per secondby a 25 watt source of monochromatic light ofwavelength 5000A°

Answer»

6000Å = 6000^-10m = 6.0^-7m

From Planck's equation .. each photon has energy, E = hc/λ (J)

If N photons are emitted per sec ..Total emission power, P = N(s⁻¹) x E(J) = NE (J/s) = 25 W

25 = NE = N x hc/λN = 25λ / hc .. 25 x 6.0^-7 / (6.625^-34 x 3.0^8) .. .. ►N = 7.55^19 photons per sec