Advertisements
Advertisements
A proton and an α-particle have the same de-Broglie wavelength Determine the ratio of their speeds.
Concept: Wave Nature of Matter
Draw a plot showing the variation of photoelectric current versus the intensity of incident radiation on a given photosensitive surface.
Concept: Photoelectric Effect - Hertz’s Observations
An electron microscope uses electrons accelerated by a voltage of 50 kV. Determine the de-Broglie wavelength associated with the electrons. Taking other factors, such as numerical aperture etc. to be same, how does the resolving power of an electron microscope compare with that of an optical microscope which used yellow light?
Concept: Davisson and Germer Experiment
A proton and an alpha particle are accelerated through the same potential. Which one of the two has (i) greater value of de−Broglie wavelength associated with it and (ii) less kinetic energy. Give reasons to justify your answer.
Concept: de-Broglie Relation
Why photoelectric effect cannot be explained on the basis of wave nature of light? Give reasons.
Concept: Wave Nature of Matter
Write the basic features of photon picture of electromagnetic radiation on which Einstein’s photoelectric equation is based.
Concept: Einstein’s Equation - Particle Nature of Light
point out any two characteristic properties of photons on which Einstein’s photoelectric equation is based ?
Concept: Einstein’s Photoelectric Equation: Energy Quantum of Radiation
Briefly explain the three observed features which can be explained by Einstein’s photoelectric equation.
Concept: Einstein’s Photoelectric Equation: Energy Quantum of Radiation
State clearly how photoelectric equation is obtained using the photon pictu.re of electromagnetic radiation.
Concept: Dual Nature of Radiation
Write the three salient features observed in photoelectric effect which can be explained using this equation.
Concept: Dual Nature of Radiation
Answer the following question.
Define the term "Threshold frequency", in the context of photoelectric emission.
Concept: Electron Emission
Why it is the frequency and not the intensity of the light source that determines whether the emission of photoelectrons will occur or not? Explain.
Concept: Experimental Study of Photoelectric Effect
Which one of the following metals does not exhibit emission of electrons from its surface when irradiated by visible light?
Concept: Photoelectric Effect - Hallwachs’ and Lenard’s Observations
Read the following paragraph and answer the questions.
| The figure shows the variation of photoelectric current measured in a photocell circuit as a function of the potential difference between the plates of the photocell when light beams A, B, C and D of different wavelengths are incident on the photocell. Examine the given figure and answer the following questions: |
- Which light beam has the highest frequency and why?
- Which light beam has the longest wavelength and why?
- Which light beam ejects photoelectrons with maximum momentum and why?
Concept: Experimental Study of Photoelectric Effect
How will the de-Broglie wavelength associated with an electron be affected when the velocity of the electron decreases? Justify your answer.
Concept: Wave Nature of Matter
How would the stopping potential for a given photosensitive surface change if the intensity of incident radiation was decreased? Justify your answer.
Concept: Experimental Study of Photoelectric Effect
How would the stopping potential for a given photosensitive surface change if the frequency of the incident radiation were increased? Justify your answer.
Concept: Experimental Study of Photoelectric Effect
How will the de-Broglie wavelength associated with an electron be affected when the accelerating potential is increased? Justify your answer.
Concept: Wave Nature of Matter
What is the effect of threshold frequency and stopping potential on increasing the frequency of the incident beam of light? Justify your answer.
Concept: Experimental Study of Photoelectric Effect
Show that the radius of the orbit in hydrogen atom varies as n2, where n is the principal quantum number of the atom.
Concept: De Broglie’s Explanation of Bohr’s Second Postulate of Quantisation
