Home
Class 12
PHYSICS
A 40 W ultraviolet light source of wavel...

A 40 W ultraviolet light source of wavelength `2480 A`. Illuminates a magnesium (mg) surface placed 2 m away. Determine the number of photons emitted from the surface per second and the number incident on unit area of Mg surface per second . The photoelectric work function for Mg is `3.68eV`. Calculate the kinetic energy of the fastest electrons ejected from the surface. Determine the maximum wavelength for which the photoelectric effects can be observed with Mg surface.

Promotional Banner

Topper's Solved these Questions

  • ELECTRONS AND PHOTONS

    SL ARORA|Exercise TYPE A : Problem For Self Practice|21 Videos

  • ELECTRONS AND PHOTONS

    SL ARORA|Exercise TYPE B : Problem For Self Practice|10 Videos

  • ELECTRONS AND PHOTONS

    SL ARORA|Exercise TYPE E : Problem For Self Practice|11 Videos

  • ELECTROMAGNETIC WAVES

    SL ARORA|Exercise Problem for self-practice|21 Videos

  • ELECTROSTATIC FORCES, CHARGES AND FIELDS

    SL ARORA|Exercise Problems For Self Practice|1 Videos

Similar Questions

Explore conceptually related problems

Ultraviolet radiation of 6.2 eV falls on a metallic surface. If the work function of the metal is 4.2 eV, then the kinetic energy of the fasted electron ejected from the surface is

The work function of tungsten is 4.50 eV. Calculate the speed of the fastest electrons ejected from a tungsten sur- face when light whose photon energy is 5.80 eV shines on the surface.

The photoelectric work function of a surface is 2.2 eV. The maximum kinetic energy of photoelectrons emitted when light of wavelength 6200 Å is incident on the surface, is

The photoelectric threshold wavelength for tungsten is 2400 Å . Determine the energy of the electrons ejected from its surface when exposed to ultraviolet radiations of wavelength 1200 Å .

Work function of a metal is 2 eV. The maximum wavelength of photons required to emit electrons from its surface is

The work function for a metal is 40 eV . To emit photo electrons of zero velocity from the surface of the metal the wavelength of incident light should be x nm .

When ultraviolet lightofenergy6.2 eV incidents on a aluminimum surface, it emits photoelectrons. If work function for aluminium surface is 4.2 eV, then kinetic energy of emitted electrons is

SL ARORA-ELECTRONS AND PHOTONS-Problem Solution
  1. The distance between the two plates of a cathode-ray oscilloscope is 1...

    Text Solution

    |

  2. An electron enters the region between the plates of a parallel plate c...

    Text Solution

    |

  3. A charged particle of radius 5xx10^(-7)m is located in a horizontal el...

    Text Solution

    |

  4. A monochromatic light soure of frequency f illuminates a metallic sur...

    Text Solution

    |

  5. A cylindrical rod of some laser material 5xx10^-2m long and 10^-2m in ...

    Text Solution

    |

  6. A 40 W ultraviolet light source of wavelength 2480 A. Illuminates a ma...

    Text Solution

    |

  7. In an experiment on photo electric emission, following observations we...

    Text Solution

    |

  8. Light of wavelength 180 nm ejects photoelectrons from a plate of met...

    Text Solution

    |

  9. When a surface is irradiated with light of wavelength 4950A, a photocu...

    Text Solution

    |

  10. The maximum KE of photoelectrons emitted from a cetain metallic surfac...

    Text Solution

    |

  11. A beam of light has three wavelengths 4144 Å, 4972 Å and 6216 Å with a...

    Text Solution

    |

  12. A light source, emitting there wavelengths 500nm, 600nm and 700 nm, ha...

    Text Solution

    |

  13. A small plate of a metal (work function =1.7eV) is placed at a distanc...

    Text Solution

    |

  14. A monochromatic point source radiating wavelength 6000Å with power 2 w...

    Text Solution

    |

  15. A neutron is an uncharged particle of mass 1.67xx10^(-27) kg. Calculat...

    Text Solution

    |

  16. Assume that the de Broglie wave associated with an electron can from a...

    Text Solution

    |

  17. When photons of energy 4.25 eV strike the surface of metal A, the ejec...

    Text Solution

    |

  18. In a photoelectric effect set up, a point source of light of power 3.2...

    Text Solution

    |

  19. The voltage across the electrodes of a cathode ray tube is 1000 V. Cal...

    Text Solution

    |