Advertisements
Advertisements
Question
Use Einstein's photoelectric equation to explain the observations from this graph ?
Advertisements
Solution
The Einstein's photoelectric equation is \[K_{max} = \frac{1}{2}m \nu^2_{max} = h\nu - \phi_o\]
From the graph, we noticed that
(i) The value of stopping potential is different for radiation of different frequencies.
\[\text { As } \]
\[e V_o = h\nu - \phi_o \]
\[\text { Hence }, V_o \propto \nu\]
(ii) The value of stopping potential is more negative for radiation of higher incident frequency.
APPEARS IN
RELATED QUESTIONS
Two monochromatic beams, one red and the other blue, have the same intensity. In which case (i) the number of photons per unit area per second is larger, (ii) the maximum kinetic energy of the photoelectrons is more? Justify your answer.
A photosensitive surface emits photoelectrons when red light falls on it. Will the surface emit photoelectrons when blue light is incident on it? Give reason.
Draw a plot showing the variation of photoelectric current with collector potential for different frequencies but same intensity of incident radiation ?
What change will you observe if intensity of incident radiation is changed but the frequency remains the same?
A beam of monochromatic radiation is incident on a photosensitive surface. Answer the following question giving reason :
On what factors does the number of emitted photoelectrons depend?
With reference to the photoelectric effect, what is meant by threshold wavelength?
Two metals A and B have work functions 4 eV and 6 eV respectively. Which metal has a lower threshold wavelength for photoelectric effect?
Light of wavelength 4000 Å is incident on two metals A and B. Which metal will emit photoelectrons, if their work functions are 3.8 e V and 1.6 e V respectively?
The phenomenon of photoelectric emission was observed by ______.
Consider an electron in front of metallic surface at a distance d (treated as an infinite plane surface). Assume the force of attraction by the plate is given as `1/4 q^2/(4πε_0d^2)`. Calculate work in taking the charge to an infinite distance from the plate. Taking d = 0.1 nm, find the work done in electron volts. [Such a force law is not valid for d < 0.1nm].
