Q. 14

# Find the maximum kinetic energy of the photoelectrons ejected when light of wavelength 350 nm is incident on a cesium surface. Work function of cesium = 1.9 eV.

Answer :

Given, wavelength λ =350nm =350 ×m

Work function of cesium Ф =1.9eV

From Einstein photoelectric equation,

hf=Kmax +Ф

where Kmax is maximum kinetic energy,

h is Planck’s constant

f is frequency (f=c/λ where c is speed of light and

λ is the wavelength of light).

∴

⇒

⇒

⇒

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