Ultra-violet light of wavelength 200 nm from a source is incident on a metal surface If the stopping potential - Physics - Dual Nature Of Radiation And Matter

Question

Ultra-violet light of wavelength 200 nm from a source is incident
on a metal surface If the stopping potential is -2 5 V,
(a) calculate the work function of the metal, and
(b) How would the surface respond to a high intensity red light of
wavelength 6328 ? produced by a laser?

Vipra Mishra · Accepted Answer

Solution
K E
max =hν -ϕϕ is work fucntionK
E max = eVoeVo =hcλ -ϕ1
6×10-19(-2 5) =6
6×10-34×3×108200×10-9 m -ϕϕ =6
6×10-34×3×108200×10-9 m+1
6×10-19(2 5) ϕ = 0
099×10-17 +4×10-19= 9
9×10-19 +4×10-19ϕ =13
9 ×10-19 J = 8
68 eVThershold wavelengthλ =hcϕ =6
6×10-34×3×10813 9 ×10-19 =1
4244×10-7=1424 ×10-10 mAs wavelength of red light is greater than thershold wavelengththe surface will not respond to a high intensity red light of wavelength

Ultra-violet light of wavelength 200 nm from a source is incident on a metal surface. If the stopping potential is -2.5 V, (a) calculate the work function of the metal, and (b) How would the surface respond to a high intensity red light of wavelength 6328 ? produced by a laser?

Ultra-violet light of wavelength 200 nm from a source is incident on a metal surface. If the stopping potential is -2.5 V,
(a) calculate the work function of the metal, and
(b) How would the surface respond to a high intensity red light of wavelength 6328 ? produced by a laser?