Home
Class 12
PHYSICS
In a photoemmisive cell,with exciting wa...

In a photoemmisive cell,with exciting waelength `lambda`,the fastest electron has speed of v.If the exciting waelength is changed to `3 lambda//4`,the speed of the fastest emitted electron will be

A

`v (3//4)^(1//2)`

B

`v (4//3)^(1//2)`

C

less than `v(3//4)^(1//2)`

D

greater than `v(4//3)^(1//2)`.

Text Solution

Verified by Experts

Promotional Banner

Topper's Solved these Questions

  • UNIT TEST -07

    MODERN PUBLICATION|Exercise EXERCISE|154 Videos

  • UNIT TEST -06

    MODERN PUBLICATION|Exercise EXERCISE|461 Videos

  • UNIT TEST-05

    MODERN PUBLICATION|Exercise EXERCISE|69 Videos

Similar Questions

Explore conceptually related problems

A cathode ray tube is operated at 2,500 V. What is the speed of electrons emitted?

The total energy of an electron in the first excited state of the hydrogen atom is about-3.4ev What is the potential energy of the electron in this state?

The total energy of an electron in the first excited state of the hydrogen atom is about-3.4ev What is the kinetic energy of the electron in this state?

The energy of seperation of an electron in a hydrogen like atom in excited state is 3.4eV. The de-Broglie wave length (in Å) associtated with the electron is :

Light from a dicharge tube containing hydrogen atoms falls on the surface of sodium.The kinetic energy of the fastest electrons emitted from sodium is 0.73 eV.The work function for sodium is 1.82 eV.find the recoil speed of the emitting atom assuming it to be at rest before the transmition.(Ionisation energy of hydrogen is 13.6 eV).

Estimate the speed with which electrons emitted from a heated emitter of an evacuated tube impinge on the collectro maintained at a potential difference of 500 V with respect to the emitter. Ignore the small initial speeds of the electrons. The specific charge of the electrons i.e. its e/m is given to be 1.76 xx 10^11 C kg^-1 .

Bohr's model of hydrogen atom In order to explain the stability of atom and its line spectra, Bohr gave a set of postulates: An electron in an atom revolves in certain circular orbit around the nucleus. These are the orbits for which mvr=(nh)/(2pi) In these allowed orbits, the electron does not radiate energy. When an electron jumps from higher energy level E_(n_2) to lower energy orbit E_(n_1) , radiation is emittd and frequency of emitted electron is given by v=(E_(n_2)-E_(n_1))/h . Further the radius of the n^(th) orbit of hydrogen atom is r=(n^2h^24piepsilon_0)/(4pi^2me^2) and energy of the n^(th) orbit is given by E_n=-13.6/n^2 eV . When hydrogen atom is the first excited level, it radius is:,

The total energy of an electron in the first excited state of the hydrogen atom is about -3.4 eV. (A) What is the kinetic energy of the electron in this state? (B) What is the potential energy of the electron in this state? (C) Which of the answers above would change if the choice of the zero of potential energy is changed?

The de-Broglie wavelength associated with an electron accelerated through a potential difference V is lambda . What will be wavelength when accelerating potential is increased to 4V?

In a sample of excited hydrogen atoms electrons make transition from n=2 to n=1. Emitted quanta strike on a metal of work function 4.2eV. Calculate the wavelength in A associated with ejected electron having maximum kinetic energy

MODERN PUBLICATION-UNIT TEST -07-EXERCISE
  1. According to Einstein's photoelectric equation, the graph between kine...

    Text Solution

    |

  2. According to Einstein's photoelectric equation, the graph between kine...

    Text Solution

    |

  3. In a photoemmisive cell,with exciting waelength lambda,the fastest ele...

    Text Solution

    |

  4. A photosensitive metallic surface has work function hv0.If photons of ...

    Text Solution

    |

  5. A photocell employs photoelectric effect to convert

    Text Solution

    |

  6. A particle of mass 1 mg has the same wavelength as an electron moving ...

    Text Solution

    |

  7. The kinetic energy of an electron,which is accelerated to the potentia...

    Text Solution

    |

  8. The mass of an electron is m, charge is e and it is accelerated form r...

    Text Solution

    |

  9. The minimum wavelength of the X-rays produced by elecrons accelerated ...

    Text Solution

    |

  10. The de-Broglie wave corresponding to a particle of mass m and velocity...

    Text Solution

    |

  11. If particles are moving with same velocity,then maximum de-Broglie wav...

    Text Solution

    |

  12. If we consider electrons and photons of same wave length, then they w...

    Text Solution

    |

  13. The momentum of a photon of energy 1 M eV(in kg m s^(-1)) will be

    Text Solution

    |

  14. An electron of mass m,when accelerated through a potensital difference...

    Text Solution

    |

  15. An electron beam has a kinetic energuy equal to 100 eV.Find the waveln...

    Text Solution

    |

  16. Electron volt is a unit of

    Text Solution

    |

  17. The energy of a photon of light of waveelngth 5,000 overset@A is appro...

    Text Solution

    |

  18. Particle nature and wave nature of electromagnetic waves and electrons...

    Text Solution

    |

  19. A strong argument for the particle nature of cathode rays is that they

    Text Solution

    |

  20. The wavelength of a photon is proportional to (where v = frequency)

    Text Solution

    |