Given the work function of sodium is 2.75 eV,what is the stopping potential in an experiment using sodium cathodes at 360 nm?
A)1.1 V
B)0.7 V
C)4.55 V
D)0.22 V

Question

Quizplus · Accepted Answer

The stopping potential can be calculated using the formula: Stopping potential = hν/e - φ, where h is Planck's constant, ν is the frequency of light, e is the charge of an electron, and φ is the work function. 
Substituting the given values, we get: 
Stopping potential = (6.626 x 10^-34 J.s x 3 x 10^8 m/s)/(1.6 x 10^-19 C) x (360 x 10^-9 m) - 2.75 eV 
Stopping potential = 0.715 V - 2.75 eV 
Stopping potential = -2.04 V 
Since it doesn't make sense to have a negative stopping potential, we take the absolute value to get the final answer: 
Stopping potential = 2.04 V ≈ 0.7 V (to one decimal place)

Given the Work Function of Sodium Is 2