Neon gas is generally used in the sign boards. If it emits strongly at 616 nm, calculate (a) the frequency of emission, (b) distance traveled by this radiation in 30 s



Q.47:- Neon gas is generally used in the sign boards. If it emits strongly at 616 nm, calculate (a) the frequency of emission, (b) distance traveled by this radiation in 30 s (c) energy of quantum and (d) number of quanta present if it produces 2 J of energy.

 

 

Answer:-

λ  = 616 nm = 616×10-9 m
(a) Frequency, ν = c/λ = 3.0×10ms-1/616×10-9 m = 4.87×1014 s-1

(b) Velocity of the radiation = 3.0×10ms-1



∴ Distance travelled in 30 s = 30×3×10m = 9.0×10m
(c) E = hν = hc/λ = (6.626×10-34 Js×3.0×10ms-1)/616×10-9 m = 32.27×10-20 J
(d) No. of quanta in 2J of energy = 2J/32.27×10-20 J = 6.2×1018