Home
Class 12
PHYSICS
A modern 200 W sodium street lamp emits ...

A modern 200 W sodium street lamp emits yellow light of wavelength 0.6 `mum`. Assuming it to be 25% efficient in converting electrical energy to light, the number of photons of yellow light it emits per second is

A

` 1.5 xx 10 ^( 20) `

B

` 6 xx 10^(18)`

C

` 6.2 xx 10^( 20) `

D

` 3 xx 10 ^(19)`

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Topper's Solved these Questions

  • PHOTOELECTRIC EFFECT

    MOTION|Exercise EXERCISE -3 (PREVIOUS YEAR PROBLEMS (JEE MAIN))|12 Videos

  • PHOTOELECTRIC EFFECT

    MOTION|Exercise EXERCISE-2 (OBJECTIVE QUESTIONS (NEET))|17 Videos

  • OPTICS

    MOTION|Exercise Exercise|45 Videos

  • PROJECTILE MOTION

    MOTION|Exercise EXERCISE-3 (SECTION-B)|8 Videos

Similar Questions

Explore conceptually related problems

A sodium street light gives off yellow light that has a wavelength of 600 n m. Then .

A sodium street light gives off yellow light that has a wavelength of 589nm . What is the frequency of this light?

A special kind of light bulb emits monochromatic light of wavelength 630 nm. Electrical energy is supplied to it at the rate of 60 W, and the bulb is 93% efficient at converting that energy to light energy. How many photons are emitted by the bulb during its lifetime of 730 h?

A 20 W lamp rated 10% emits light of wavelength y. Calculate the number of photons emitted by the lamp per second.

A 100 watt bult emits monochromatic light of wavelength 400 nm. Calcualte the number of photons emitted per second by the bulb.

A 100 watt bulb emits monochromatic light of wavelength 400 nm. Calculate the number of photons emitted per second by the bulb.

MOTION-PHOTOELECTRIC EFFECT -EXERCISE - 3 SECTION -A (Previous Year Problems (NEET ))
  1. The work functions for metals A, B and C are respectively 1.92 eV, 2....

    Text Solution

    |

  2. Monochromatic light of wavelength 667 nm is produced by a helium neon ...

    Text Solution

    |

  3. Light of two different frequencies whose photons have energies 1eV and...

    Text Solution

    |

  4. In photoelectric emission process from a metal of work function 1.8 eV...

    Text Solution

    |

  5. The threshold frequency for a photosensitive metal is 3.3 xx 10^(14) H...

    Text Solution

    |

  6. An electron in the hydrogen atom jumps from excited state n to the gro...

    Text Solution

    |

  7. Monochromatic radiation emitted when electron on hydrogen atom jumps f...

    Text Solution

    |

  8. A modern 200 W sodium street lamp emits yellow light of wavelength 0.6...

    Text Solution

    |

  9. A alpha -parhticle moves in a circular path of radius 0.83 cm in th...

    Text Solution

    |

  10. An electrons of a stationary hydrogen aton passes form the fifth enegr...

    Text Solution

    |

  11. Threshold frequency of a metal is 5xx10^(13)s^(-1) upon which 1xx10^(1...

    Text Solution

    |

  12. The wavelength lambda(e ) of an electron and lambda(p) of a photon of...

    Text Solution

    |

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

    Text Solution

    |

  14. When the energy of the incident radiation is increased by 20 % , kinet...

    Text Solution

    |

  15. When a metallic surface is illuminated with radiation of wavelength la...

    Text Solution

    |

  16. An electron of mass m and a photon have same energy E. The ratio of de...

    Text Solution

    |

  17. Photons with energy 5 eV are incident on a cathode C in a photoelectri...

    Text Solution

    |

  18. The photoelectric threshold wavelength of silver is 3250 xx 10^(-10) m...

    Text Solution

    |

  19. An electron of mass m with an initial velocity vec(v) = v(0) hat(i) ...

    Text Solution

    |

  20. When the light of frequency 2 v(0) (where v(0) is threshold frequency)...

    Text Solution

    |