stopping potential and kinetic energy of electron

stopping potential and kinetic energy of electron


1 Answers

Aman Bansal
592 Points
9 years ago

Dear Najid,

KE(max)=hf - work function
KE(max)=e(delta Vs)
delta Vs=stopping potential
delta Vs= (hf)/e - (work function)/e
which is same thing as
delta Vs=(hc)/(e*wavelength) - (work function)/e

*you need to find the value of work function to find the new stopping potential.
Stopping potential=2.10 v
Stopping potential= hc/e*wavelength - work function/e
Stopping potential= (6.63e-34 J*sec)(3.00e8m/s)/(290e-9m)(1.60e-19) - work function
work function= 2.186637931 V

using this, you get
New Stopping potential= 0.6386461599 Volt
The stopping potential is the potential (energy/unit charge) or (Joules/Coulomb) that must be applied to stop the electrons from being ejected from the surface when the light is shone on it. If the energy of the incident photon is greater than the work required to remove the electron from the surface plus the applie (-) potential, electrons will leave the surface with some kinetic energy. The stopping potential is the applied potential that makes this KE=0

qV(s)=E(photon)-q(work function)
V(s)=hv/q - work function

V(s)=stopping potential
and hv/q is same thing as hc/q(lambda)

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Aman Bansal

Askiitian Expert

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