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Medical
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The momentum of a photon of energy h v will be

  • Option 1)

    \frac{hv}{c}

  • Option 2)

    \frac{c}{hv}

  • Option 3)

    hv

  • Option 4)

    \frac{hv}{c^{2}}

 
As we discussed in concept Kinetic mass of photon - - wherein        For photon E = pc. =>   Option 1) This option is  correct. Option 2) This option is incorrect. Option 3) This option is incorrect. Option 4) This option is incorrect.
Medical
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Photoelectric emmision occurs only when the incident light has more than a certain minimum

  • Option 1)

    power

  • Option 2)

    wavelength

  • Option 3)

    intensity

  • Option 4)

    frequency

 
As we discussed in concept Threshold frequency - The minimum frequency of incident radiation to eject electron is threshold frequency () - wherein If incident frequency No photoelectron emission    Photoelectrons emitted when incident light has energy or frequency more than a certain minimum value caused threshold frequency.   Option 1) power This option is incorrect. Option...
Medical
218 Views   |  

In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by

  • Option 1)

    increasing the potential difference between the anode and filament

  • Option 2)

    increasing the filament current

  • Option 3)

    decreasing the filament current

  • Option 4)

    decreasing the potential difference between the anode and filament

 
As we discussed in concept Galvanometer in Davisson Germer Experiment - To measure the small values of current: - wherein    Electron is accelerated by applying potential difference between anode & cathode hence velocity of electron emitted from the electron gun can be increased by increasing potential difference between the anode and the filament.   Option 1) increasing the potential...
Medical
94 Views   |  

The threshold frequency for a photosensitive metal is 3.3\times 10^{14} Hz. If light of frequency 8.2\times 10^{14} Hz is incident on this metal, the cut-off voltage for the photoelectric emission is nearly

  • Option 1)

    2V

  • Option 2)

    3V

  • Option 3)

    5V

  • Option 4)

    1V

 
As we discussed in concept Conservation of energy -   - wherein    & Stopping Potential /Cut-off Potential - It is defined as the potential necessary to stop any electron from reaching the other side. -             =         =     Option 1) 2V This option is correct. Option 2) 3V This option is incorrect. Option 3) 5V This option is incorrect. Option 4) 1V This option is incorrect.
Medical
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Light of two different frequencies whose photons have energies 1 eV and 2.5eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speeds of emitted electrons will be

  • Option 1)

    1:4

  • Option 2)

    1:2

  • Option 3)

    1:1

  • Option 4)

    1:5

 
As we discussed in concept Conservation of energy -   - wherein     Option 1) 1:4 This option is incorrect. Option 2) 1:2 This option is correct. Option 3) 1:1 This option is incorrect. Option 4) 1:5 This option is incorrect.
Medical
135 Views   |  

In photoelectric emission process from a metal of work function 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding stopping potential is

  • Option 1)

    1.8 V

  • Option 2)

    1.2 V

  • Option 3)

    0.5 V

  • Option 4)

    2.3 V

 
As we discussed in concept Stopping Potential /Cut-off Potential - It is defined as the potential necessary to stop any electron from reaching the other side. -    Stopping potential is amount of voltage needed to stop maximum energy electron. Here maximum Kinetic energy = 0.5 eV Stopping potential = 0.5 V   Option 1) 1.8 V This option is incorrect. Option 2) 1.2 V This option is...
Medical
117 Views   |  

Electron used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100 kV then the de-Broglie wavelength associated with the electrons would

  • Option 1)

    increase by 2 times

  • Option 2)

    decrease by 2 times

  • Option 3)

    increase by 4 times

  • Option 4)

    increase by 4 times

 
As we discussed in concept De - Broglie wavelength with charged particle -   - wherein     wavelength decreases by a factor of 2.   Option 1) increase by 2 times This option incorrect. Option 2) decrease by 2 times This option correct. Option 3) increase by 4 times This option incorrect. Option 4) increase by 4 times This option incorrect.
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