4.5eV
3.0eV
15.1eV
1.5eV
The maximum kinetic energy of the emitted electrons (Kmax) in the photoelectric effect is given by:
Kmax = hν - φ
where h is Planck's constant, ν is the frequency of the incident light, and φ is the work function of the metal.
The work function can be expressed in terms of the threshold wavelength (λ0):
φ = hc/λ0
where c is the speed of light.
The energy of the incident light can be expressed in terms of its wavelength (λ):
E = hc/λ
Substituting these expressions into the equation for Kmax, we get:
Kmax = hc/λ - hc/λ0 = hc(1/λ - 1/λ0)
Given that E(in eV) = 1237/λ(in nm), we can rewrite the equation for Kmax as:
Kmax = 1237(1/λ - 1/λ0) eV
Substituting the given values, λ = 260 nm and λ0 = 380 nm:
Kmax = 1237(1/260 - 1/380) eV
Kmax = 1237(0.003846 - 0.002632) eV
Kmax = 1237(0.001214) eV
Kmax ≈ 1.5 eV