Question

A sample of silver (with work function φ = 4.52 ev) is exposed to an ultraviolet light source (λ= 200 nm), which results in the ejection of photoelectrons. what changes will be observed if:

Answer 1

The photoelectric effect involves ejecting electrons from a metal surface when exposed to light with adequate energy. For silver with a work function of 4.52 eV, ultraviolet light of 200 nm wavelength will eject photoelectrons. Changes such as shorter wavelength or increased light intensity can result in more photoelectrons with higher kinetic energy.

Step-by-step explanation:

The question pertains to the photoelectric effect, a phenomenon in physics where photons hitting a metal surface can eject electrons from that surface if the incident light has enough energy. The photoelectric effect is observed when the energy of the incident photons is greater than the work function of the metal. For silver, the work function is given as 4.52 eV. When ultraviolet light with a wavelength of 200 nm (which corresponds to a photon energy greater than 4.52 eV) strikes a silver surface, photoelectrons will be ejected. If the wavelength of the incident light is reduced or the intensity of the light is increased, more photoelectrons can be emitted with greater kinetic energy.

Answer 2

Work function of metal = hc/e h=planck's constant c=speed of light in vacuum = threshold wavelength = 285nm e=1.6 x 10^-19 So = (6.63x10^-34)x (3 x 10^8)/(285x10^-9 x 1.6 x 10^-19) =4.36 eV Maximum energy of emitted electrons = Energy incident - work function = hc/e (where =140nm) =(6.63x10^-34)x (3 x 10^8)/(140x10^-9 x 1.6 x 10^-19) - 4.36 =8.88 - 4.36 = 4.52 eV