The critical wavelength for producing the photoelectric effect in tungsten metal is 2600 angstrom. what wavelength would be necessary to produce photoelectrons from tungsten having twice the kinetic energy of those produced in 2200 angstrom
Answers
Answered by
31
Let :
Critical wavelength = w°
Wavelength when kinetic energy is normal = w₁
When K. E is doubled = w₂
K. E₁ = 1 / w₁ — 1/ w°
K. E₂ = 2K.E₁
K. E₂ = 1 / w₂ — 1 / w°
1 / w₂ — 1 / w° = 2 / w₁ —2 / w°
1 / w₂ = 2 / w₁ — 1 / w°
Doing the substitution :
1 / w₂ = 2 / 2200 — 1/ 2600
1 / w₂ = (2600 — 1100) / 2860000
1 / w₂ = 1500 / 2860000
w₂ = 2860000 / 1500 = 1906.667 Angstroms
Critical wavelength = w°
Wavelength when kinetic energy is normal = w₁
When K. E is doubled = w₂
K. E₁ = 1 / w₁ — 1/ w°
K. E₂ = 2K.E₁
K. E₂ = 1 / w₂ — 1 / w°
1 / w₂ — 1 / w° = 2 / w₁ —2 / w°
1 / w₂ = 2 / w₁ — 1 / w°
Doing the substitution :
1 / w₂ = 2 / 2200 — 1/ 2600
1 / w₂ = (2600 — 1100) / 2860000
1 / w₂ = 1500 / 2860000
w₂ = 2860000 / 1500 = 1906.667 Angstroms
Answered by
2
Answer: critical wavelength means wavelength corresponding to thersold frequency.
Explanation:
Attachments:
Similar questions