JEE Main & Advanced Physics Photo Electric Effect, X- Rays & Matter Waves Question Bank

done Topic Test - Photo Electric Effect, X-Rays & Matter Waves Total Questions - 40

• question_answer1)
  The idea of matter waves was given by
  A)
  Davisson and Germer      done clear
  B)
  de-Broglie done clear
  C)
  Einstein done clear
  D)
  Planck done clear
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• question_answer2)
  The de-Broglie wavelength \[\lambda \] associated with an electron having kinetic energy E is given by the expression
  A)
  \[\frac{h}{\sqrt{2mE}}\] done clear
  B)
  \[\frac{2h}{mE}\] done clear
  C)
  \[2mhE\] done clear
  D)
  \[\frac{2\sqrt{2mE}}{h}\] done clear
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• question_answer3)
  The de-Broglie wavelength of an electron having \[80eV\] of energy is nearly             (\[1\,eV=\text{ }1.6\times {{10}^{19}}J,\]  Mass of electron \[=9\times {{10}^{-31}}kg\] Plank’s constant \[=6.6\times {{10}^{-34}}J\text{-}\,\sec \])
  A)
  140 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  B)
  0.14 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  C)
  14 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  D)
  1.4 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
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• question_answer4)
  The kinetic energy of electron and proton is \[{{10}^{-32}}J\]. Then the relation between their de-Broglie wavelengths is
  A)
  \[{{\lambda }_{p}}<{{\lambda }_{e}}\] done clear
  B)
  \[{{\lambda }_{p}}>{{\lambda }_{e}}\] done clear
  C)
  \[{{\lambda }_{p}}={{\lambda }_{e}}\] done clear
  D)
  \[{{\lambda }_{p}}=2{{\lambda }_{e}}\] done clear
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• question_answer5)
  The kinetic energy of an electron with de-Broglie wavelength of 0.3 nanometer is        
  A)
  0.168 eV done clear
  B)
  16.8 eV done clear
  C)
  1.68 eV done clear
  D)
  2.5 eV done clear
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• question_answer6)
  de-Broglie wavelength of a body of mass m and kinetic energy E is given by              
  A)
  \[\lambda =\frac{h}{mE}\] done clear
  B)
  \[\lambda =\frac{\sqrt{2mE}}{h}\] done clear
  C)
  \[\lambda =\frac{h}{2mE}\] done clear
  D)
  \[\lambda =\frac{h}{\sqrt{2mE}}\] done clear
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• question_answer7)
  The momentum of a photon is \[2\times {{10}^{-16}}\]gm-cm/sec. Its energy is
  A)
  \[0.61\times {{10}^{-26}}erg\] done clear
  B)
  \[2.0\times {{10}^{-26}}erg\] done clear
  C)
  \[6\times {{10}^{-6}}erg\] done clear
  D)
  \[6\times {{10}^{-8}}erg\] done clear
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• question_answer8)
  The approximate wavelength of  a photon of energy 2.48 eV is                                
  A)
  500 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  B)
  5000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  C)
  2000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  D)
  1000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
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• question_answer9)
  Wavelength of a 1 keV photon is \[1.24\times {{10}^{-9}}m\]. What is the frequency of 1 MeV photon          
  A)
  \[1.24\times {{10}^{15}}Hz\]    done clear
  B)
  \[2.4\times {{10}^{20}}Hz\] done clear
  C)
  \[1.24\times {{10}^{18}}Hz\]    done clear
  D)
  \[2.4\times {{10}^{23}}Hz\] done clear
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• question_answer10)
  A photon of wavelength 4400 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] is passing through vacuum. The effective mass and momentum of the photon are respectively 
  A)
  \[5\times {{10}^{-36}}kg,\,\,1.5\times {{10}^{-27}}\,kg\text{-}m/s\] done clear
  B)
  \[5\times {{10}^{-35}}kg,\,\,1.5\times {{10}^{-26}}kg\text{-}m/s\] done clear
  C)
  Zero, \[1.5\times {{10}^{-26}}\,kg\text{-}m/s\] done clear
  D)
  \[5\times {{10}^{-36}}kg,\,1.67\times {{10}^{-43}}kg\text{-}m/s\] done clear
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• question_answer11)
  Kinetic energy with which the electrons are emitted from the metal surface due to photoelectric effect is
  A)
  Independent of the intensity of illumination done clear
  B)
  Independent of the frequency of light done clear
  C)
  Inversely proportional to the intensity of illumination done clear
  D)
  Directly proportional to the intensity of illumination done clear
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• question_answer12)
  The electrons are emitted in the photoelectric effect from a metal surface                   
  A)
  Only if the frequency of the incident radiation is above a certain threshold value done clear
  B)
  Only if the temperature of the surface is high done clear
  C)
  At a rate that is independent of the nature of the metal done clear
  D)
  With a maximum velocity proportional to the frequency of the incident radiation done clear
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• question_answer13)
  Ultraviolet radiations of \[6.2\,eV\] falls on an aluminium surface (work function \[4.2\ eV\]). The kinetic energy in joules of the fastest electron emitted is approximately   
  A)
  \[3.2\times {{10}^{-21}}\] done clear
  B)
  \[3.2\times {{10}^{-19}}\] done clear
  C)
  \[3.2\times {{10}^{-17}}\] done clear
  D)
  \[3.2\times {{10}^{-15}}\] done clear
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• question_answer14)
  Light of wavelength 4000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] is incident on a sodium surface for which the threshold wave length of photo – electrons is 5420 \[\overset{\text{o}}{\mathop{\text{A}}}\,\]. The work function of sodium is   
  A)
  4.58 eV done clear
  B)
  2.29 eV done clear
  C)
  1.14 eV done clear
  D)
  0.57 eV done clear
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• question_answer15)
  Light of wavelength 4000 Å falls on a photosensitive metal and a negative 2V potential stops the emitted electrons. The work function of the material (in eV) is approximately             \[(h=6.6\times {{10}^{-34}}Js,\ \ e=1.6\times {{10}^{-19}}C,\ \ c=3\times {{10}^{8}}m{{s}^{-1}})\]
  A)
  1.1 done clear
  B)
  2.0 done clear
  C)
  2.2 done clear
  D)
  3.1 done clear
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• question_answer16)
  As the intensity of incident light increases
  A)
  Photoelectric current increases done clear
  B)
  Photoelectric current decreases done clear
  C)
  Kinetic energy of emitted photoelectrons increases done clear
  D)
  Kinetic energy of emitted photoelectrons decreases done clear
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• question_answer17)
  The photoelectric threshold wavelength of a certain metal is 3000\[\overset{\text{o}}{\mathop{\text{A}}}\,\]. If the radiation of 2000\[\overset{\text{o}}{\mathop{\text{A}}}\,\] is incident on the metal
  A)
  Electrons will be emitted done clear
  B)
  Positrons will be emitted done clear
  C)
  Protons will be emitted done clear
  D)
  Electrons will not be emitted done clear
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• question_answer18)
  4 eV is the energy of the incident photon and the work function in \[2eV.\] What is the stopping potential
  A)
  2V done clear
  B)
  4V done clear
  C)
  6V done clear
  D)
  \[2\sqrt{2}V\] done clear
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• question_answer19)
  The number of photons of wavelength 540 nm emitted per second by an electric bulb of power 100W is (taking h = \[6\times {{10}^{-34}}\,J\text{-}sec\])
  A)
  100 done clear
  B)
  1000 done clear
  C)
  \[3\times {{10}^{20}}\] done clear
  D)
  \[3\times {{10}^{18}}\] done clear
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• question_answer20)

  Consider the two following statements A and B and identify the correct choice given in the answers;

  [A] In photovlotaic cells the photoelectric current produced is not proportional to the, intensity of incident light.

  [B] In gas filled photoemissive cells, the velocity of photoelectrons depends on the wavelength of the incident radiation.

  A)
  Both A and B are true     done clear
  B)
  Both A and B are false done clear
  C)
  A is true but B is false      done clear
  D)
  A is false B is true done clear
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• question_answer21)
  In photoelectric effect, the K.E. of electrons emitted from the metal surface depends upon
  A)
  Intensity of light done clear
  B)
  Frequency of incident light done clear
  C)
  Velocity of incident light done clear
  D)
  Both intensity and velocity of light done clear
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• question_answer22)
  A photon of energy 8 eV is incident on metal surface of threshold frequency \[1.6\times {{10}^{15}}Hz.\] The maximum kinetic energy of the photoelectrons emitted (in eV) (Take \[h=6\times {{10}^{-34}}Js)\].   
  A)
  1.6 done clear
  B)
  6 done clear
  C)
  2 done clear
  D)
  1.2 done clear
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• question_answer23)
  A photon, an electron and a uranium nucleus all have the same wavelength. The one with the most energy       
  A)
  Is the photon done clear
  B)
  Is the electron done clear
  C)
  Is the uranium nucleus done clear
  D)
  Depends upon the wavelength and the properties of the particle. done clear
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• question_answer24)
  An electron of mass m when accelerated through a potential difference V has de-Broglie wavelength \[\lambda \]. The de-Broglie wavelength associated with a proton of mass M accelerated through the same potential difference will be
  A)
  \[\lambda \frac{m}{M}\] done clear
  B)
  \[\lambda \sqrt{\frac{m}{M}}\] done clear
  C)
  \[\lambda \frac{M}{m}\] done clear
  D)
  \[\lambda \sqrt{\frac{M}{m}}\] done clear
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• question_answer25)
  Particle nature and wave nature of electromagnetic waves and electrons can be shown by
  A)
  Electron has small mass, deflected by the metal sheet done clear
  B)
  X-ray is diffracted, reflected by thick metal sheet done clear
  C)
  Light is refracted and defracted done clear
  D)
  Photoelectricity and electron microscopy done clear
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• question_answer26)
  For moving ball of cricket, the correct statement about de-Broglie wavelength is                      
  A)
  It is not applicable for such big particle done clear
  B)
  \[\frac{h}{\sqrt{2mE}}\] done clear
  C)
  \[\sqrt{\frac{h}{2mE}}\] done clear
  D)
  \[\frac{h}{2mE}\] done clear
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• question_answer27)
  The wavelength associated with an electron accelerated through a potential difference of 100 V is nearly
  A)
  100 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  B)
  123 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  C)
  1.23 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  D)
  0.123 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
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• question_answer28)
  The wavelength of the matter wave is independent of
  A)
  Mass done clear
  B)
  Velocity done clear
  C)
  Momentum done clear
  D)
  Charge done clear
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• question_answer29)
  A photon in motion has a mass               
  A)
  \[c/h\nu \] done clear
  B)
  \[h/\nu \] done clear
  C)
  \[h\nu \] done clear
  D)
  \[h\nu /{{c}^{2}}\] done clear
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• question_answer30)
  The energy of a photon of light with wavelength 5000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] is approximately 2.5 eV. This way the energy of an X-ray photon with wavelength 1\[\overset{\text{o}}{\mathop{\text{A}}}\,\] would be
  A)
   2.5/5000 eV done clear
  B)
  \[2.5/{{(5000)}^{2}}eV\] done clear
  C)
  \[2.5\times 5000\ eV\]      done clear
  D)
  \[2.5\times {{(5000)}^{2}}eV\] done clear
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• question_answer31)
  There are \[{{n}_{1}}\] photons of frequency \[{{\gamma }_{1}}\] in a beam of light. In an equally energetic beam, there are \[{{n}_{2}}\] photons of frequency \[{{\gamma }_{2}}\]. Then the correct relation is
  A)
   \[\frac{{{n}_{1}}}{{{n}_{2}}}=1\] done clear
  B)
  \[\frac{{{n}_{1}}}{{{n}_{2}}}=\frac{{{\gamma }_{1}}}{{{\gamma }_{2}}}\] done clear
  C)
  \[\frac{{{n}_{1}}}{{{n}_{2}}}=\frac{{{\gamma }_{2}}}{{{\gamma }_{1}}}\] done clear
  D)
  \[\frac{{{n}_{1}}}{{{n}_{2}}}=\frac{\gamma _{1}^{2}}{\gamma _{2}^{2}}\] done clear
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• question_answer32)
  The photo-electrons emitted from a surface of sodium metal are such that                 
  A)
  They all are of the same frequency done clear
  B)
  They have the same kinetic energy done clear
  C)
  They have the same de Broglie wavelength done clear
  D)
  They have their speeds varying from zero to a certain maximum done clear
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• question_answer33)
  The retarding potential for having zero photo-electron current                                   
  A)
  Is proportional to the wavelength of incident light done clear
  B)
  Increases uniformly with the increase in the wavelength of incident light done clear
  C)
  Is proportional to the frequency of incident light done clear
  D)
  Increases uniformly with the increase in the frequency of incident light wave done clear
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• question_answer34)
  A radio transmitter operates at a frequency of 880 kHz and a power of 10 kW. The number of photons emitted per second are           
  A)
  \[1.72\times {{10}^{31}}\] done clear
  B)
  \[1327\times {{10}^{34}}\] done clear
  C)
  \[13.27\times {{10}^{34}}\]      done clear
  D)
  \[0.075\times {{10}^{-34}}\] done clear
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• question_answer35)
  Stopping potential for photoelectrons        
  A)
  Does not depend on the frequency of the incident light done clear
  B)
  Does not depend upon the nature of the cathode material done clear
  C)
  Depends on both the frequency of the incident light and nature of the cathode material done clear
  D)
  Depends upon the intensity of the incident light done clear
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• question_answer36)
  When a point source of light is at a distance of one metre from a photo cell, the cut off voltage is found to be V. If the same source is placed at 2 m distance from photo cell, the cut off voltage will be
  A)
  V done clear
  B)
  V/2 done clear
  C)
  V/4 done clear
  D)
  \[V/\sqrt{2}\] done clear
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• question_answer37)
  Work function of a metal is 2.1 eV. Which of the waves of the following wavelengths will be able to emit photoelectrons from its surface 
  A)
  4000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\], 7500 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  B)
  5500 \[\overset{\text{o}}{\mathop{\text{A}}}\,\], 6000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  C)
  4000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\], 6000 \[\overset{\text{o}}{\mathop{\text{A}}}\,\] done clear
  D)
  None of these done clear
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• question_answer38)
  A beam of light of wavelength \[\lambda \] and with illumination L falls on a clean surface of sodium. If N photoelectrons are emitted each with kinetic energy E, then
  A)
  \[N\propto L\] and \[E\propto L\] done clear
  B)
   \[N\propto L\]and \[E\propto \frac{1}{\lambda }\] done clear
  C)
  \[N\propto \lambda \] and \[E\propto L\] done clear
  D)
  \[N\propto \frac{1}{\lambda }\]and \[E\propto \frac{1}{L}\] done clear
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• question_answer39)
  In photoelectric effect if the intensity of light is doubled then maximum kinetic energy of photoelectrons will become
  A)
  Double done clear
  B)
  Half done clear
  C)
  Four time done clear
  D)
  No change done clear
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• question_answer40)
  Light of frequency \[8\times {{10}^{15}}Hz\] is incident on a substance of photoelectric work function \[6.125\,eV.\] The maximum kinetic energy of the emitted photoelectrons is
  A)
  17\[eV\] done clear
  B)
  22\[eV\] done clear
  C)
  27\[eV\] done clear
  D)
  37\[eV\] done clear
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