Home
Class 12
PHYSICS
When light of wavelength lambda is incid...

When light of wavelength `lambda` is incident on a metal surface, stopping potential is found to be x. When light of wavelength `nlambda` is incident on the same metal surface, stopping potential is found to be `(x)/(n+1)` . Find the threshold wavelength of the metal.

Text Solution

Verified by Experts

Let `lambda_(0)` is the threshold wavelength. The work function is `phi = (hc)/(lambda_(0))`
Now, by photoelectric equation `ex = (hc)/(lambda) - (hc)/(lambda_(0))` ……(i) `(ex)/(n+1) = (hc)/(nlambda) - (hc)/(lambda_(0))`……..(ii)
From (i) and (ii) `(hc)/(lambda) - (hc)/(lambda_(0)) = (n+1) (hc)/(nlambda) - (n+1) (hc)/(lambda_(0)) rArr (nhc)/(lambda_(0)) = (hc)/(nlambda) rArr lambda_(0) = n^(2)lambda`
Promotional Banner

Topper's Solved these Questions

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise Photo Elertric Effectric : Solved Example|1 Videos

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise Matter Waves Theory : Solved Example|4 Videos

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise X Rays : Solved Example|2 Videos

  • RACE

    ALLEN |Exercise Basic Maths (Wave Motion & Dopplers Effect) (Stationary waves & doppler effect, beats)|25 Videos

  • TEST PAPER

    ALLEN |Exercise PHYSICS|4 Videos

Similar Questions

Explore conceptually related problems

Value of stopping potential depends on……. Of incident light.

When photon of wavelength lambda_(1) are incident on an isolated shere supended by an insulated , the corresponding stopping potential is found to be V . When photon of wavelength lambda_(2) are used , the orresponding stopping potential was thrice the above value. If light of wavelength lambda_(3) is used , carculate the stopping potential for this case.

A certain metallic surface is illuminated with monochromatic light of wavelength lambda .The stopping potentail for photelectric current for this light is 3V_(0) .If the same surface is illuminated with light of wavelength 2lambda ,the stopping potential is V_(0) .The threshold wavelength for this surface for photoelectric effect is

Light of wavelength 200 nm incident on a metal surface of threshold wavelength 400 nm kinetic energy of fastest photoelectron will be

Four photon of lambda gt lambda_(0) are incident on metal surface ……..photo -electron will be emitted.

Frequency of radiation incident on metal surface is called threshold frequency.

Light of wavelength 488 nm is produced by an argon laser which is used in the photoelectric effect. When light from this spectral line is incident on the emitter, the stopping (cut-off) potential of photoelectrons is 0.38 V. Find the work function of the material from which the emitter is made.

When a metallic surface is illuminated with radiation of wavelength lambda ,the stopping potential is V.If the same surface is illuminated with radiation of wavelength 2 lambda ,the metallic surface is

When a metallic surface is illuminated by a monochromatic light of lamda the stopping potential for photoelectric current is 4V_(0) when the same surface is illuminated by light of wavelength 3 lamda the stopping potential is V_(0) The threshold wavelength for this surface for photoelectric effect is -