Home
Class 12
PHYSICS
The photoelectric work - function of po...

The photoelectric work - function of potassium is 2.3 eV. If light
having a wavelength of `2800 Å` falls on potassium, find
(a) the kinetic energy in electron volts of the most energetic electrons ejected.
(b) the stopping potential in volts.

A

2.1 eV , 2.1V

B

2.3 eV , 2.4V

C

4.2 eV , 4.1V

D

4.5 eV , 2.7V

Text Solution

Verified by Experts

The correct Answer is:
A
Given, `W=2.3eV,lamda=2800`Å
`therefore` E(in eV)=`(12375)/(lamda("in Å"))`
`=(12375)/(2800)`
`=4.4eV`
`K_(max)=E-W`
`=(4.4-2.3)eV=2.1eV`
Promotional Banner

Topper's Solved these Questions

  • ELECTRONS AND PROTONS

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise Exercise 1|50 Videos

  • ELECTRONS AND PROTONS

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise Exercise 2|29 Videos

  • ELECTROMAGNETIC INDUCTION

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise MHT CET CONER|34 Videos

  • ELECTROSTATICS

    MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS|Exercise MHT CET Corner|29 Videos

Similar Questions

Explore conceptually related problems

The photoelectric work function of potassium is 3.0 eV. If light having a wavelength of 2475 Å falls on potassium. Find the stopping potential in volts.

The photoelectric work function for potassium is 2 eV . The light of wavelength 3.6 xx 10^(-7) m falls on potassium . The stopping potential is

The photoelectric work function for sodium is 2.7 eV. If light of frequency 9.0xx10^14 Hz falls on sodium, find (a) the stopping potential, (b)the kinetic energy of the most energetic electrons ejected , and (c ) the speed of those electrons.

If light of wavelength 6200Å falls on a photosensitive surface of work function 2 eV, the kinetic energy of the most energetic photoelectron will be

Ultraviolet light of 6.2eV falls on Caesium surface (work function = 1.2eV) . The kinetic energy (in electron volts) of the fastest electron emitted is approximately

The work function of a metal is 3.4 eV. A light of wavelength 3000Å is incident on it. The maximum kinetic energy of the ejected electron will be :

The photoelectric work function for aluminium is 4.2 eV. What is the stopping potential for radiation of wavelength 2500 Å ?

The work function of a certain metal is 2.3 eV. If light of wave number 2 xx 10^(6)m^(-1) falls on it, the kinetic energies of fastest and slowest ejected electron will be respectively.

Photoelectric work- function of a metal is 1 eV. Light of wavelength lambda = 3000 Å falls on it. The photoelectrons come out with maximum velocity

Work function of a metal surface is phi=1.5eV . If a light of wavelength 5000Å falls on it then the maximum K.E. of ejected electron will be-

MHTCET PREVIOUS YEAR PAPERS AND PRACTICE PAPERS-ELECTRONS AND PROTONS-MHT CET CORNER
  1. The photoelectric work - function of potassium is 2.3 eV. If light h...

    Text Solution

    |

  2. Light of wavelength A which is less than threshold wavelength is incid...

    Text Solution

    |

  3. When light of wavelength lambda is incident on photosensitive surface,...

    Text Solution

    |

  4. The de-Broglie wavelength lamda

    Text Solution

    |

  5. For photoelectric emission from certain metal the cut - off frequency ...

    Text Solution

    |

  6. The wavelength lamda(e) of ann electron and lamda(p) of a photon of sa...

    Text Solution

    |

  7. The ratio of moment of an electron and an alpha-particle which are acc...

    Text Solution

    |

  8. When the kinetic energy of an electron is increased , the wavelength o...

    Text Solution

    |

  9. The dimensions of Planck's constant is the same as the product of

    Text Solution

    |

  10. In photoelectric effect if the intensity of light is doubled then maxi...

    Text Solution

    |

  11. Which of the following is not the property of the photons ?

    Text Solution

    |

  12. The momentum of a photon of energy 1 MeV in kg m//s will be

    Text Solution

    |

  13. As the intensity of incident light increases

    Text Solution

    |

  14. A photoelectric cell is illuminated by a point source of light 1 m awa...

    Text Solution

    |

  15. A red bulb and violet bulb of equal power emits n(R ) and n(v) number ...

    Text Solution

    |

  16. An electron is accelerated from rest to potential V. the final velocit...

    Text Solution

    |

  17. The dual nature of light is exhibited by

    Text Solution

    |

  18. Energy of photon whose frequency is 10^(12) MHz, will be

    Text Solution

    |

  19. Number of electrons emitted by a surface exposed to light is directly ...

    Text Solution

    |

  20. The (e)/(m) value of electron is

    Text Solution

    |