Light of wavelength 488 nm is produced by an argon laser which isused in the photoelectric effect. When light from this spectral line isincident on the emitter, the stopping (cut-off) potential ofphotoelectrons is 0.38 V. Find the work function of the material from which the emitter is made.
Given: The wavelength of light produced by an argon laser is 488 nm and the stopping potential of the photo electrons is 0.38 V .
The work function is given as,
ϕ 0 = h c λ − e V 0
Where, the charge on electron is e , Planck’s constant is h , the stopping potential is V 0 , the speed of light is c and the wavelength is λ .
By substituting the given values in the above equation, we get
ϕ 0 = 6.6 × 10 − 34 × 3 × 10 8 1.6 × 10 − 19 × 488 × 10 − 9 − 1.6 × 10 − 19 × 0.2375 × 10 19 = 2.54 − 0.38 = 2.16 eV
Thus, the work function of the material is 2.16 eV .
Given: The wavelength of light produced by an argon laser is
The work function is given as,
Where, the charge on electron is
By substituting the given values in the above equation, we get
Thus, the work function of the material is
