Home
Class 12
PHYSICS
Monochromatic light of frequency 6.0xx10...

Monochromatic light of frequency `6.0xx10^(14)Hz` is produced by a laser. The power emitted is `2.0xx10^(-3)`W. (a). What is the energy of a photon in the light beam? (b) How many photons per second, on an average are emitted by the source?

Text Solution

Verified by Experts

a. Each photon has an energy
`E=h upsilon=(6.63.10^(-34)Js)(6.0xx10^(14)Hz)=3.98xx10^(-19)J`
b. If N is the number of photons emitted by the source per second, the power P transmitted in the beam equals N times the energy per photon E, so that P = N E. Then
`N=(P)/(E )=(2.0xx10^(-3))/(3.98xx10^(-19))=5.0xx10^(15)` photons per second.
Promotional Banner

Topper's Solved these Questions

  • DUAL NATURE OF RADIATION AND MATTER

    NEW JOYTHI PUBLICATION|Exercise SOLUTIONS TO EXERCISES FROM NCERT TEXT|18 Videos

  • DUAL NATURE OF RADIATION AND MATTER

    NEW JOYTHI PUBLICATION|Exercise PRACTICE PROBLEMS FOR SELF ASSESSMENT|5 Videos

  • CURRENT ELECTRICITY

    NEW JOYTHI PUBLICATION|Exercise COMPETITIVE EXAM CORNER|37 Videos

  • ELECTRIC CHARGES AND FIELDS

    NEW JOYTHI PUBLICATION|Exercise Competitive Exam Corner|20 Videos

Similar Questions

Explore conceptually related problems

Monochromatic light of frequency 6 xx 10^(14) Hz is produced by a laser. The power emitted is 2.0 xx 10^(-3) W . How many photons per second on an average are emitted by the source ?

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 is 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). c. How fast does a hydrogen atom have to travel in order to have the same momentum as that of the photon?

How many photons of frequency 10^(14) Hz will make up 19.86 J of energy ?

How many photons are emitted per second by a 5 m W laser source operating at 632.8nm?

A parallel beam of monochromatic light of wavelength 500nm is incident normally on a perfectly absorbing surface. The power through any cross- section of the beam is 10 W. Find (a) the number of photons absorbed per second by the surface and (b) the force exerted by the light beam on the surface.

In a plane electromagnetic wave of frequency 1.0xx10^(12) Hz, the amplitude of the magnetic field is 5.0xx10^(-6)T . a. Calculate the amplitude of the electric field. b. What is the total average energy density ?