Home
Class 12
PHYSICS
If a source of power 4 kW produces 10^20...

If a source of power 4 kW produces `10^20` photons per second, the radiation belongs to a part of spectrum called

A

`gamma`-rays

B

X-rays

C

ultraviolet rays

D

microwaves.

Text Solution

Verified by Experts

The correct Answer is:
B
`p=(E)/(t)=(4hd)/(t)=(4c)/(lambdat)`
or `(6.6xx10^(-34)xx3xx10^(8))/(4xx10^(3))xx10^(20)=(19.8)/(4)xx10^(-9)`
`~=50Å` (X-rays)
Promotional Banner

Topper's Solved these Questions

  • ELECTRONS & PHOTONS

    MODERN PUBLICATION|Exercise MULTIPLE CHOICE QUESTIONS (LEVEL-II)|63 Videos

  • ELECTRONS & PHOTONS

    MODERN PUBLICATION|Exercise MULTIPLE CHOICE QUESTIONS (LEVEL-III)|9 Videos

  • ELECTROMAGNETIC WAVES

    MODERN PUBLICATION|Exercise RECENT COMPETITIVE QUESTIONS|4 Videos

  • ELECTROSTATICS

    MODERN PUBLICATION|Exercise RECENT COMPETITIVE QUESTIONS |39 Videos

Similar Questions

Explore conceptually related problems

4.4 keV radiations belong to the spectrum portion of

The energy flux of sunlight reaching the surface of Earth is 1.388 xx10^(3)Wm^(-2) . How many photons per square meter are incident on Earth per second? Assume the wavelength of photon at an average of 550 nm.

A cycle wheel with 64 spokes is rotatory at the rate of 120 revolutions per second. A potential difference of 10 V is produced between the axis and the rim. What will be this potential difference, if the number of spokes is reduced to 16 ?

(a) An X-ray tube produces a continuous spectrum of radiation with its short wavelength end at 0.45 Å . What is the maximum energy of a photon in the radiation? (b) From your answer to (a), guess what order of accelerating voltage (for electrons) is required in such a tube ?

Monochromatic light of wavelength 632.8 nm is produced by a helium-neon laser. The power emitted is 9.42 mW. (a) Find the energy and momentum of each photon in the light beam, (b) How many photons per second, on the average, arrive at a target irradiated by this beam? (Assume the beam to have uniform cross-section which is less than the target area), and (c) How fast does a hydrogen atom have to travel in order to have the same momentum as that of the photon?

A stone is dropped into a quiet lake and waves in circles at a speed of 4 cm per second. At the instant, when the radius of the circular wave is 10 cm, how fast is the enclosed area increasing?

MODERN PUBLICATION-ELECTRONS & PHOTONS-RECENT COMPETITIVE QUESTIONS
  1. If a source of power 4 kW produces 10^20 photons per second, the radia...

    Text Solution

    |

  2. According to Einstein's photoelectric equation the graph of K.E. of th...

    Text Solution

    |

  3. An electron is moving in an orbit of a hydrogen atom from which there ...

    Text Solution

    |

  4. v(1) is the frequency of the series limit of Lyman series, v(2) is te ...

    Text Solution

    |

  5. The de-Broglie wavelength of the electron in the ground state of the h...

    Text Solution

    |

  6. The photoelectric threshold wavelength for silver in lambda(0).The ene...

    Text Solution

    |

  7. An electron of mass m(e) and a proton of mass m(p) are moving with the...

    Text Solution

    |

  8. Pick out the wrong statement.

    Text Solution

    |

  9. A proton and an alpha particle are accelerated through the same potent...

    Text Solution

    |

  10. In hydrogen atom , electron excites from ground state of higher energy...

    Text Solution

    |

  11. An alpha - particle and a proton moving with the same kinetic energy e...

    Text Solution

    |

  12. X- rays, gamma rays and microwaves travelling in vacuum have

    Text Solution

    |

  13. If n is the orbit number of the electron in a hydrogen atom , the corr...

    Text Solution

    |

  14. A charged particle with a velocity 2 xx 10^3 ms^-1 passes undeflected ...

    Text Solution

    |

  15. Maximum velocity of the photoelectron emitted by a metal is 1.8 xx 10^...

    Text Solution

    |

  16. lamda(1) and lamda(2) are used to illuminated the slits. beta(1) and b...

    Text Solution

    |

  17. What is the de Broglie wavelength of the electron accelerated through ...

    Text Solution

    |

  18. The maximum kinetic energy of emitted photoelectrons depends on

    Text Solution

    |

  19. Find the de-Broglie wavelength of an electron with kinetic energy of 1...

    Text Solution

    |

  20. Light of two different frequencies whose photons have energies 1 eV an...

    Text Solution

    |

  21. The best waves for emission of electrons from a surface :

    Text Solution

    |