Home
Class 12
PHYSICS
A monochromatic source of light is place...

A monochromatic source of light is placed at a distance d from a metal surface photoelectrons are ejected at n, kinetic energy being E. If the source is brought nearer to distance `d/2`. The rate and kinetic energy per photo electron becomes nearly

A

12n and 2E

B

4nand 4E

C

4n and E

D

n and 4E

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • MODEL QUESTION PAPER -3

    SARAS PUBLICATION|Exercise EXERCISE|45 Videos
  • MODEL QUESTION PAPER 2

    SARAS PUBLICATION|Exercise EXERCISE|43 Videos

Similar Questions

Explore conceptually related problems

A 5 watt source emites monochromatic light of wavelenght 5000 overset@A . When placed 0.5m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0m, the number of photo electrons liberates will:

A source of light is placed at a distance of 50 cm from a photo cell and the stopping Potential is found to be V_0 . If the distance between the light surface and photo cell is made 25 cm, the new stopping potential will be

A point source of monochromatic light of 1.0 mW is placed at a distance of 5.0 m from a metal surface. Light falls perpendicularly on the surface. Assume wave theory of light to hold and also that all the light falling on the circular area with radius =1.0 xx 10^-9m (which is few times the diameter of an atom) is absorbed by a single electron on the surface. Calculate the time required by the electron to receive sufficient energy to come out of the metal if the work function of the metal is 2.0eV .

Two beams, one of red light and the other of blue light, of the same intensity are incident on a metallic surface to emit photoelectrons. Which one of the two beams emits electrons of greater kinetic energy ?

A source S and a detector D are placed at a distance d apart. A big cardboard is placed at a distance sqrt2d from the source and the detector as shown in figure. The source emits a wave of wavelength = d/2 which is received by the detector after reflection from the cardboard. It is found to be in phase with the direct wave received from the source. By what minimum distance should the cardboard be shifted away so that the reflected wave becomes out of phase with the direct wave ?

Photoelectric effect supports quantum nature of light because (a) there is a minimum frequency of light below which no photo electrons are emitted (b) the maximum kinetic energy of photo electrons depends only on the frequency of light and not on its intensity (c ) even when the metal surface is faintly illuminated, the photo electrons leave the surface immediately (d) electric charge of the photo electrons is quantised

The work function of caesium metal is 2.14 eV. When light of frequency 6xx10^(14)Hz is incident on the metal surface, photoemission of electrons occurs. What is the a. maximum kinetic energy of the emitted electrons, b. stopping potential, and c. maximum speed of the emitted photoelectrons ?

A small piece of cesium metal phi=1.9eV is kept at a distance of 20 cm form a large metal plate having a charge density of 1.0xx 10^-9 C m^-2 on the surface facing the cesium piece. A monochromatic light of wavelength 400nm is incident on the cesium piece. Find the minimum and the maximum kinetic energy of the photoelectrons reaching the large metal plate. Neglect any change in electric field due to the small piece of cesium present.

A point source emitting alpha particles is placed at a distance of 1 m from a counter which records any alpha particle falling on its 1 cm^2 window. If the source contains 6.0xx10^16 active nuclei and the counter records a rate of 50000 counts//second, find the decay constant. Assume that the source emits alpha particles fall nearly normally on the window.

Light corresponding to the transition n = 4 to n = 2 in hydrogen atom falls on cesium metal (work function = 1.9 eV) Find the maximum kinetic energy of the photoelectrons emitted

SARAS PUBLICATION-MODEL QUESTION PAPER 1-EXERCISE
  1. A current 1 ampere is passed through a straight wire of length 2.0 met...

    Text Solution

    |

  2. The dimensions of magnetic field intensity H are

    Text Solution

    |

  3. A wire is situated in the eastwest direction and the current flowing t...

    Text Solution

    |

  4. A long solenoid 200 turns// cm and carries a current I. The magnetic f...

    Text Solution

    |

  5. If mu0=4pixx10^(-7)TmA^(-1) and epsilon0=8.85xx10^-2C^2N^(-1)m^(-2). T...

    Text Solution

    |

  6. ...... has the shortest wavelength

    Text Solution

    |

  7. The minimum distance between the object and its real image for concave...

    Text Solution

    |

  8. The angle of incident at which reflected light is totally polarised fo...

    Text Solution

    |

  9. A monochromatic source of light is placed at a distance d from a metal...

    Text Solution

    |

  10. The work function for the surface of aluminium is 4.2 eV. What will be...

    Text Solution

    |

  11. When a radio active isotopes "88Ra^228 decays in series by the emissio...

    Text Solution

    |

  12. A position is emitted by a radio active nucleus of at omic number 90.T...

    Text Solution

    |

  13. Complete the table

    Text Solution

    |

  14. Which one of the following has more volume. Iron block or a wooden blo...

    Text Solution

    |

  15. Tritium has a half-life of 12.5 y undergoing beta decay. What fraction...

    Text Solution

    |

  16. The dark lines in the solar spectrum are called lines.

    Text Solution

    |

  17. In an P.N.P transistor circuit, the collector current is 10 mA. If 90%...

    Text Solution

    |

  18. Focal length of an equiconvex lens is 20 cm. If we cut it once perpend...

    Text Solution

    |

  19. A black body is continously radiating energy at a temperature of ...

    Text Solution

    |

  20. The wavelength of the Ka line for the uranium atom (z = 92) is (R = 10...

    Text Solution

    |