Home
Class 12
PHYSICS
A 100 W sodium lamp is radiating light o...

A 100 W sodium lamp is radiating light of wavelength `5890A`, uniformly in all directions,
a. At what rate, photons are emitted from the lamp?
b. At what distance from the lamp, the average flux is 1 photon(`cm^2-s)^-1?`
c. What are the photon flux and photon density at 2m from the lamp?

Text Solution

Verified by Experts

(a) `2.96xx10^(20)"photon/s,"` (b) `4.86xx10^(7)m,` (c) `5.89xx10^(18)("photons")/(m^(2).s)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • PHOTONS AND MATTER WAVES

    RESNICK AND HALLIDAY|Exercise PRACTICE QUESTIONS (Single Correct Choice Type)|47 Videos
  • PHOTONS AND MATTER WAVES

    RESNICK AND HALLIDAY|Exercise PRACTICE QUESTIONS (More than One Correct Choice Type)|5 Videos
  • PHOTONS AND MATTER WAVES

    RESNICK AND HALLIDAY|Exercise Check points|3 Videos
  • OSCILLATIONS

    RESNICK AND HALLIDAY|Exercise Practice Questions|57 Videos
  • RELATIVITY

    RESNICK AND HALLIDAY|Exercise PRACTICE QUESTIONS (Integer Type)|5 Videos

Similar Questions

Explore conceptually related problems

What is the highest frequency of a photon that can be emitted from a hydrogen atom ? What is the wavelength of this this photon ?

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

Knowledge Check

  • A 160 watt infrared source is radiating light of wavelength 50000Å uniformly in all directions. The photon flux at a distance of 1.18 m is of the order of -

    A
    `10 m^(-2)s^(-1)`
    B
    `10^(10)m^(-2)s^(-1)`
    C
    `10^(15)m^(-2)s^(-1)`
    D
    `10^(20)m^(-2)s^(-1)`
  • A 160 watt light source is radiating light of wavelength 6200 Å uniformly in all directions. The photon flux at a distance of 1.8 m is of the order of (Planck's constant 6.63xx 10^(-34) J-s)

    A
    `10^(2)m^(-2)s^(-1)`
    B
    `10^(12)m^(-2)s^(-1)`
    C
    `10^(19)m^(-2)s^(-1)`
    D
    `10^(25)m^(-2)s^(-1)`
  • A 160 watt light source is radiating light of wavelength 6200 Å uniformly in all directions. The photon flux at a distance of 1.8 m is of the order of (Plank's constant 6.62 xx 10^(-34) J-s )

    A
    `10^(2) m^(-2)s^(-1)`
    B
    `10^(12) m^(-2)s^(-1)`
    C
    `10^(19) m^(-2) s^(-1)`
    D
    `10^(25) m^(-2) s^(-1)`
  • Similar Questions

    Explore conceptually related problems

    A 100W sodium lamp radiates energy uniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on it. The wavelength of the sodium light is 589nm. (a) What is energy associated per photon with the sodium light? (b) At what rate are photons delivered to the sphere?

    A 100W sodium lamp radiates energyuniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on it. The wavelength of the sodium light is 589 nm. (a) what is the energy per photon associated with the sodium light? (b) At what rate are the photons delivered to the sphere ?

    A lamp radiates power P_(0) uniformly in all directions, the amplitude of elctric field strength E_(0) at a distance r from it is

    10^(20) photons of wavelength 660 nm are emitted per second from a lamp . What is the wattage of the lamp ?

    A 60 W bulb is placed at a distance of 4 m from you. The bulb is emtting light of wavelength 600 nm uniformly in all directions. In 0.1 s, how many photons enter your eye if the pupil of the eye is having a diameter of 2mm? [take hc=1240eV-nm]