Home
Class 12
PHYSICS
An important spetral emission line has a...

An important spetral emission line has a wavelength of 21 cm. The corresponding photon energy is
`(h=6.62 xx10^(-34)Js ,c=3xx10^(8)m//s)`

A

`5.9 xx 10^(-4) eV`

B

`5.9 xx 10^(-6) eV`

C

`5.9 xx 10^(-8) eV`

D

`11.8 xx 10^(-6) eV`

Text Solution

Verified by Experts

`E=(hc)/(lambda)=(3xx10^(8)xx6.62xx10^(-34))/(0.21xx1.6xx10^(-19))=5.9xx10^(-6)eV`
Promotional Banner

Topper's Solved these Questions

  • DUAL NATURE OF RADIATION AND MATTER

    NARAYNA|Exercise EXERCISE - 2 (C.W)|25 Videos

  • DUAL NATURE OF RADIATION AND MATTER

    NARAYNA|Exercise EXERCISE - 2 (H.W)|20 Videos

  • DUAL NATURE OF RADIATION AND MATTER

    NARAYNA|Exercise EXERCISE - 1 (C.W)|40 Videos

  • CURRENT ELECTRICITY

    NARAYNA|Exercise Level 6|43 Videos

  • DUAL NATURE

    NARAYNA|Exercise LEVEL-II (H.W)|17 Videos

Similar Questions

Explore conceptually related problems

What is the wavelength of light . Given energy =3.03xx10^(-19)J, h=6.6xx10^(-34)JS, c=3.0xx10^(8)m//s ?

An X - ray tube produces a continuous spectrum of radiation with its shortest wavelength of 45xx10^(-2)Å . The maximum energy of a photon in the radiation in eV is (h = 6.62xx10^(-34)Js, c=3xx10^(8)ms^(-1))

A Photon of red light having wavelength 600 nm has energy equal of (h=6.6xx10^(-34)Js) :

A monochromatic source of light operating at 500W emits 6xx10^(20) photon per second. Find the wavelength of the light used. Use h=6.6xx10^(-34)Js , C=3xx10^8m//s

The work function for a certain metal is 4.2eV. Will this metal give photoelectric emission for incident radiation of wavelength 330nm? Given, charge on electron, e=1.6xx10^(-19)C, c=3xx10^(8)m//s, h=6.62xx10^(-34)Js .

If a semiconductor photodiode can detect a photon with a maximum wavelength of 400 nm, then its band gap energy is : Planck's constant h= 6.63 xx 10^(-34) J.s Speed of light c= 3xx10^8 m//s

Calculate the de-Broglie wavelength of an electron moving with one fifth of the speed of light. Neglect relativistic effects. (h=6.63 xx 10^(-34) J.s., c=3xx10^(8)m//s , mass of electron =9xx10^(-31)kg)

The work function of a metal is 2.5eV . The maximum kinetic energy of the photoelectrons emitted if a radiof wavelength 3000A^(0) falls on it is (h=6.63xx10^(-34)Js & c=3xx10^(8)m//s)

The energy of X-ray photon of wavelength 1.65 Å is (h=6.6 xx 10^(-34)J-sec,c=3xx10^(8)ms^(-1),1eV=1.6xx10^(-19)J)

NARAYNA-DUAL NATURE OF RADIATION AND MATTER-EXERCISE - 1 (H.W)
  1. A metal of work function 4eV is cexposed to a radiation of wavelegth 1...

    Text Solution

    |

  2. Threshold wavelength for a metal having work function w(0) is lambda. ...

    Text Solution

    |

  3. The work functions of metals A and B are in the ratio 1 : 2. If light ...

    Text Solution

    |

  4. The threshold wavelength for photoelectric emission from a material ...

    Text Solution

    |

  5. An AIR station is broadcasting the waves of wavelength 300 metres. If ...

    Text Solution

    |

  6. The energy of a photon is E = hv and the momentum of photon p = (h)/(l...

    Text Solution

    |

  7. The approximate wavelength of a photon of energy 2.48 eV is

    Text Solution

    |

  8. An important spetral emission line has a wavelength of 21 cm. The corr...

    Text Solution

    |

  9. A particle having a de Broglie wavelength of 1.0 A^(0) is associated w...

    Text Solution

    |

  10. The de - Broglie wavelength of an electron having 80 ev of energy is n...

    Text Solution

    |

  11. Electrons are accelerated through a p.d. Of 150V. Given m=9.1xx10^(-31...

    Text Solution

    |

  12. If accelerating potential of an alpha particle is doubled than its new...

    Text Solution

    |

  13. The ratio of the deBroglie wavelengths of proton, deuteron and alpha p...

    Text Solution

    |

  14. The energy that should be added to an electron, to reduce its de-Brogl...

    Text Solution

    |

  15. The de - Broglie wavelength of an electron having 80 ev of energy is n...

    Text Solution

    |

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

    Text Solution

    |

  17. The wavelength of most energetic X-rays emitted when a metal target is...

    Text Solution

    |

  18. X - rays which can penetrate through longer distances in substance are...

    Text Solution

    |

  19. An X - ray machine has an accelerating potential difference of 25,000 ...

    Text Solution

    |

  20. Four the production of X-rays of wavelength 0.1 Å the minimum potentia...

    Text Solution

    |