Home
Class 12
PHYSICS
A 2 mW laser operates at a wavelength of...

A 2 mW laser operates at a wavelength of 500 nm. The number of photons that will be emitted per second is: [Given Planck’s constant `h = 6.6 xx 10^(-34)Js`, speed of light `c = 3.0 xx 10^(8) m//s`]

Text Solution

Verified by Experts

Energy of photon (E) is given by
`E=(hc)/(lamda)`
Numbr of photons of wavelength `lamda` emitted in t second from laser of power P is give by
`n=(P t lamda)/(hc)`
`impliesn=(2xxlamda)/(hc)=(2xx10^(-3)xx5xx10^(-7))/(2xx10^(-25))" "( :. t=1S)`
`impliesn=5xx10^(15)`
Promotional Banner

Topper's Solved these Questions

  • CHAPTERWISE NUMERIC /INTEGER ANSWER QUESTIONS

    DISHA PUBLICATION|Exercise CHAPTER 26 : (ATOMS)|15 Videos

  • CHAPTERWISE NUMERIC /INTEGER ANSWER QUESTIONS

    DISHA PUBLICATION|Exercise CHAPTER 27 : (NUCLEI)|15 Videos

  • CHAPTERWISE NUMERIC /INTEGER ANSWER QUESTIONS

    DISHA PUBLICATION|Exercise CHAPTER 24 : (WAVE OPTICS)|15 Videos

  • ATOMS

    DISHA PUBLICATION|Exercise EXERCISE-2: CONCEPT APPLICATOR|30 Videos

  • COMMUNICATION SYSTEM

    DISHA PUBLICATION|Exercise EXERCISE-2 : Concept Applicator|30 Videos

Similar Questions

Explore conceptually related problems

The energy of a photon wavelength k = 1 meter is (Planck's constant = 6.625 xx 10^(-34) Js, speed of light = 3 xx 10^(8) m//s )

If a semiconductor photodiode can detect a photon with a maximum wavelength of 400 nm, then its band gap energy is : Planck's constant h= 6.63 xx 10^(-34) J.s Speed of light c= 3xx10^8 m//s

Calculate the energy in joule corresponding to light of wavelength 45 nm : (Planck' constant h = 6.63 xx 10^-34 Js , speed of light c = 3 xx 10^8 ms^-1 )

The number of photons of wavelength 540 nm emitted per second by an electric bulb of power 100 W is (taking h = 6 xx 10^(-34) sec )

The momentum of a photon of de Broglie wavelength 5000Å is …………… . [Plank's constant =6.63xx10^(-34)J.s ]