Plus Two Physics Chapter Wise Previous Questions Chapter 11 Dual Nature of Radiation and Matter is part of Kerala Plus Two Physics Chapter Wise Previous Questions and Answers Kerala. Here we have given Plus Two Physics Chapter Wise Questions and Answers Chapter 11 Dual Nature of Radiation and Matter.
Kerala Plus Two Physics Chapter Wise Previous Questions and Answers Chapter 11 Dual Nature of Radiation and Matter
The given graph shows the variation of KE with frequency of incident radiations for two surfaces A and B. [March-2018]
a. Which of the,two metals has greater work function ? For which of the metals will stopping potential be more for the same frequency of incident radiation ?
b. The work function of caesium metal is 2.14eV. When light of frequency 6×1014Hz incident on the metal surface, what is the maximum KE of the photo electrons and stopping potential ?
a. B has greater work function.
A has more stopping potential since φ0 decreases, then V0 increases for same incident frequency.
Momentum of a photon with wavelength λ is ……………….
iv. h+ λ
Photoelectric current does not depend on energy of the radiation, but on its intensity. Explain. [March-2017]
Photoelectric effect is one photon – one electron phenomenon. Therefore, when the intensity of radiation incident on the surface increases the number of photons per unit area unit time increases. Hence, the photoelectron ejected will be large, which in turn, will contribute to the increase in photoelectric current. The energy of the emitted electrons does not depend on the intensity of the incoming light. So photoelectric current does not depend on energy of the radiation
The work function of a metal is 6 eV. If two photons each having energy 4 eV strike with the metal surface
(i) will the emission be possible ?
b. The waves associated with matter is called matter waves. Let Xe and Xp be the de -Broglie wavelengths associated with electron and proton respectively. If they are accelerated by same potential, then
a. (i) No
(ii) Free electrons are bound to the metal with some force. The minimum energy required to liberate an electron from the metal is called work function, here the energy of one photon is less than work function. So emission will not be possible,
b. (i) λe > λp
i. What is de Broglie hypothesis ?
ii. Write the formula for de-Broglie wave length.
iii. Calculate de Broglie wavelength as sociated with an electron accelerated by a potential difference of 100 volts.
Given mass of the electron=9.1×10-31 kg, h=6.634×10-34 Js,1 eV=1.6×10-19 J. [March-2015]
i. He proposed that material particles in motion should display wave-like properties.
i. Work function of a metal is the energy
a. required by an electron to get absorbed in the metal surface.
b. minimum energy required by an electron to escape from the metal surface.
c. energy required by an electron to be retained in the metal surface.
d. maximum energy required by an electron to escape from the metal surface.
ii. Write Einstein’s Photo-Electric Equation and explain the terms in it.
iii. All Photo electrons are not emitted with the same energy as the incident photons. Why? [March-2015]
i. b. minimum energy required by an electron to escape from the metal surface.
iii. All the photo electrons emitted from the metal do not have the same energy. Photoelectric current is zero when the stopping potential is sufficient to repel even the most energetic photo electrons, with the maximum kinetic energy (Kmax),
Albert Einstein, the great physist proposed a clear picture to explain photoelectric effect.
a. Explain Einstein’s photo electric equation.
b. Name the quanta of light. [March-2014]
Photon is a quanta of light.
a. Who introduced the concept of photon?
b. Briefly explain the effect of intensity and energy of the incident radiation on the photo electric effect. [March-2013]
a. Albert Einstein.
b. As the intensity increases the no. of photo electrons increases. As the energy of incident photon increases the K.E of the photo electrons increases.
To emit a free electron from a metal surface a minimum amount of energy must be supplied. [March-2011 ]
a. This energy is called………………
b. State three methods to supply this energy to the free electron.
c. When light of o = 7.21 x 1014 Hz is incident on a metal surface, the max speed of ejected electron is
6 ×105 m/s. Calculate the threshhold frequency for the metal.
a. Work function.
b. Thermionic emission, field emission and photo electric emission.
We hope the Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 11 Dual Nature of Radiation and Matter help you. If you have any query regarding Kerala Plus Two Chemistry Chapter Wise Questions and Answers Chapter 11 Dual Nature of Radiation and Matter, drop a comment below and we will get back to you at the earliest.