Home
Class 12
PHYSICS
A monochromatic source of light operatin...

A monochromatic source of light operating at 200W
emits `4 xx 10^20` photons per second. Find the wavelength
of the light.

Text Solution

Verified by Experts

Power `P=(n)/(t)(hc)/(lamda)`
Energy of Photon `E=(P)/((N/(t)))=(200)/(4xx10^(20))=5xx10^(-19)J`
`lamda=4xx10^(20)xx(6.6xx10^(-34)xx3xx10^(8))/(200)=3960Å`
Promotional Banner

Topper's Solved these Questions

  • DUAL NATURE OF RADIATION AND MATTER

    AAKASH SERIES|Exercise EXERCISE-I|65 Videos

  • DUAL NATURE OF RADIATION AND MATTER

    AAKASH SERIES|Exercise EXERCISE-I ASSERTION AND REASON|4 Videos

  • CURRENT ELECTRICITY

    AAKASH SERIES|Exercise EXERCISE - IA|2 Videos

  • ELECTRIC CHARGES AND FIELDS

    AAKASH SERIES|Exercise Practice Exercise|57 Videos

Similar Questions

Explore conceptually related problems

What is power (in watt) of a light source emitting 4.25 xx 10^(18) photons per second, while the wavelength of light is 620 nm ? (use hc = 12400 eVÅ )

A monochromatic light source of intensity 5 mW emits (8xx10^15) photons per second . This light ejects photoelectrons from a metal surface. The stopping potential for this setup is 2.0 V. Calculate the work function of the metal.

What is power (in watt) of a light source emitting 7.25 xx 10^(18) photons per second, while the wavelength of light is 620 nm ? (use hc = 12400 eVÅ )

What is power (in watt) of a light source emitting 3.125 xx 10^(18) photons per second, while the wavelength of light is 620 nm ? (use hc = 12400 eVÅ )

What is power (in watt) of a light source emitting 5.25 xx 10^(18) photons per second, while the wavelength of light is 620 nm ? (use hc = 12400 eVÅ )

The electric field associated with a monochromatic beam of light becomes zero, 1.2xx10^15 times per second. Find the maximum kinetic energy of the photoelectrons when this light falls on a metal surface whose work function is 2.0eV, h=6.63xx10^(-34)Js .

Why can’t two independent monochromatic sources of light emitting light of one and the same wavelength behave as coherent sources?

The luminous flux of a monochromatic source of 1 W is 450 lumen W^-1 . Find the relative luminosity at the wavelength emitted.

The time taken by a monochromatic light to travel a certain distance in air in 9 xx 10^(-6) seconds. The time taken by the light ray to travel the same distance in water of refractive index (4)/(3) is

Consider a 20 W light source that emits monochromatic light of wavelength 600 nm . The number of photons ejected per second in terms of Avogadro's constant (N_(A)) is approximately

AAKASH SERIES-DUAL NATURE OF RADIATION AND MATTER-PRACTICE EXERCISEX
  1. A monochromatic source of light operating at 200W emits 4 xx 10^20 ...

    Text Solution

    |

  2. Two separate monochromatic light beams A and B of the same intensity (...

    Text Solution

    |

  3. The maximum kinetic energy of an electron is E when the incident wavel...

    Text Solution

    |

  4. Two sources A and B have same power . The wavelength of radiation of A...

    Text Solution

    |

  5. The photo electric threshold wavelength for a metal is 2750A^(@), The ...

    Text Solution

    |

  6. When the incident wavelengths are lamda and lamda//2 the kinetic energ...

    Text Solution

    |

  7. A 1 kw radio transmitter operates at a frequency of 880 KHz how many p...

    Text Solution

    |

  8. The threshold wavelength for photo electric emission from a material i...

    Text Solution

    |

  9. Light of wavelength 4000A∘ is incident on a metal surface. The maximum...

    Text Solution

    |

  10. Monochromatic light incident on a metal surface emits electrons with k...

    Text Solution

    |

  11. Three metals have work functions in the ratio 2 3:4. Graphs are drawn ...

    Text Solution

    |

  12. Two photons of energies twice and thrice the work function of a metal ...

    Text Solution

    |

  13. The work function of substance is 4.0 eV. The longest wavelength of li...

    Text Solution

    |

  14. Photoelectric work function of a metal is 1eV, light of wavelength lam...

    Text Solution

    |

  15. When a monochromatic point source of light is at a distance of 0.2 m...

    Text Solution

    |

  16. The work function of a substance is 12.4 eV. The longest wavelength of...

    Text Solution

    |

  17. A surface irradiated with light of wavelength 480 nm gives out electro...

    Text Solution

    |

  18. What P.D. must be applied to stop the fastest photo electron emitted b...

    Text Solution

    |

  19. The threshold frequency for photo electric effect for a metal surface ...

    Text Solution

    |

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

    Text Solution

    |

  21. When a metal surface is illuminated by light of wavelengths 400 nm and...

    Text Solution

    |