Question

a bulb is emitting emr of wavelength 20 angstrom and power of the bulb is 100 watts. Fine the number of quantum emitted by the bulb in 3 hours.​

Answer 1

Answer:

Power of the bulb = 100 watt = 100Js −1

Energy of one photon is E=hν=hc/λ

where, h=6.626×10 −34Js,c=3×10 8ms −1

Given λ=400nm=400×10 −9m

By putting the values, we get

E=6.626×10 −34×3×10 8/(400×10 −9)

E=4.969×10 −19J

Number of photons emitted in 1 sec × energy of one photon = power

n×4.969×10 −19=100

n= 4.969×10 −19100

n=2.012×10 20photons per sec