Relativistic corrections become necessary when the expression for the kinetic energy \(\frac { 1 }{ 2 } m{ v }^{ 2 }\) becomes comparable with \(m{ c }^{ 2 }\) where m is the mass of the particle. At what de-Broglie wavelength will relativistic corrections become important for an electron?

Two photons, each of energy 2.5eV are simultaneously incident on the metal surface. If the work function of the metal is 4.5eV, then from the surface of metal

Silver has a work function of 4.7eV when ultraviolet light of wavelength 100 nm is incident upon it, a potential 0f 7.7 is required to stop the photoelectrons from reaching the collector plate.How much potential will be required to stop the photoelectrons when light of wavelength 200 nm is incident upon silver? 

The ratio between masses of two particles is 1:2 and ratio between their temperatures is also 1:2 The ratio between their de-Broglie wavelength

The threshold wavelength for photoelectric emission for a material is 5200\(\mathring { A } \). Will the photoelectrons be emitted when this material is illuminated with monochromatic radiation from the 1-watt ultraviolet lamp?

What is the effect of a decrease in frequency of incident radiation on the stopping potential in photoelectric emission?

de-Broglie wavelength associated with an electron accelerated through a potential difference V is \({ \lambda }.\) What will be its wavelength when the accelerating potential is increased to 4V?

The intensity of light depends upon the........present in light.

de-Broglie waves are associated with a moving particle irrespective of.........on it.

What is the role of photocell in cinematography?

An electron and photon possessing same K.E. Which one will have greater wavelength?

In Davisson – Germer experiment if the angle of diffraction is 520 find Glancing angle?

What is the energy associated with a photon of wavelength 6000 A⁰ ?

Explain the term stopping potential and a threshold frequency.

For a photosensitive surface, threshold wavelength is.\({ \lambda }_{ 0 }\) Does photoemission occur if the wavelength of the incident radiation is (i) more than \({ \lambda }_{ 0 }\) (ii) less than\({ \lambda }_{ 0 }\) Justify your answer?

The work function for a certain metal is 4.2eV. Will this metal give photoelectric emission for incident radiation of wavelength 330 nm? Use, \(h=6.6\times { 10 }^{ -34 }Js\)

What is the de Broglie wavelength associated with
(a) an electron moving with a speed of 5.4 x 10⁶m/s
(b)a ball of mass 150g travelling at 30.0m/s?

What is the de-Broglie wavelength of a nitrogen molecule is moving with the root-mean-square speed of molecules at this temperature. (Atomic mass of nitrogen = 14.0076 u)

Radiation has dual nature,i.e., it possesses the properties of both; wave and particle.This prompted de-Broglie to predict dual nature of moving material particles.Thus waves are associated with moving material particles which are called matter waves. The wavelength of matter wave is given by \(\lambda =\frac { h }{ mv } \), where m is the mass, v is the speed of the particle and h is Plank's constant. Read the above paragraph and answer the following questions;
(i) How was the wave nature of the electron established?
(ii) What are the de-Broglie wavelength associated with a particle (i) at rest (ii) moving with infinite speed?
(iii) What are the basic values displayed with this study?

By how much would the stopping potential for a given photosensitive surface go up if the frequency of the incident radiations were to be increased from \(4\times { 10 }^{ 5 }Hz\) to \(8\times { 10 }^{ 15 }Hz\)? Given, \(h=6.6\times { 10 }^{ -34 }Js,e=1.6\times { 10 }^{ -19 }C \ and \ c=3\times { 10 }^{ 8 }{ ms }^{ -1 }\)

The extent of localisation of a particle is determined by its de-Broglie wavelength.If an electron is localised within the nucleus(of size about \({ 10 }^{ -14 }\))of an atom, what is it energy? Compare this energy with the typical binding energies(of the order of a few MeV) in a nucleus and hence argue why electron cannot reside in a nucleus.