English
Tamil Nadu Board of Secondary EducationHSC Science Class 12

Emission of electrons by the absorption of heat energy is called ____________ emission.

Advertisements
Advertisements

Question

Emission of electrons by the absorption of heat energy is called ____________ emission.

Options

  • photoelectric

  • field

  • thermionic

  • secondary

MCQ
Fill in the Blanks
Advertisements

Solution

Emission of electrons by the absorption of heat energy is called thermionic emission.

shaalaa.com
  Is there an error in this question or solution?
Chapter 8: Dual Nature of Radiation and Matter - Evaluation [Page 136]

APPEARS IN

Samacheer Kalvi Physics - Volume 1 and 2 [English] Class 12 TN Board
Chapter 8 Dual Nature of Radiation and Matter
Evaluation | Q I. 15. | Page 136

RELATED QUESTIONS

Find the (a) maximum frequency and (b) minimum wavelength of X-rays produced by 30 kV electrons.


The work function of caesium metal is 2.14 eV. When light of frequency 6 × 1014 Hz is incident on the metal surface, photoemission of electrons occurs. What is the

  1. maximum kinetic energy of the emitted electrons,
  2. Stopping potential, and
  3. maximum speed of the emitted photoelectrons?

Why should gases be insulators at ordinary pressures and start conducting at very low pressures?


The work function of the following metals is given : Na 2.75 ev, K = 2.3 eV, Mo = 4.17 eV and Ni = 5.15 eV. Which of these metals will not cause photoelectric emission for radiation of wavelength 3300 Å from a laser source placed 1 m away from these metals? What happens if the laser source is brought nearer and placed 50 cm away?


Why does thermionic emission not take place in non-conductors?


Define the term "Threshold frequency", in the context of photoelectric emission.  


Answer the following question.
Define the term "Threshold frequency", in the context of photoelectric emission.


What do you mean by electron emission? Explain briefly various methods of electron emission.


A 150 W lamp emits light of the mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.


Photoelectric emission is observed from a metallic surface for frequencies ν1 and ν2 of the incident light (ν1 > ν2). If the maximum value of kinetic energy of the photoelectrons emitted in the two cases are in the ration 1 : n then the threshold frequency of the metallic surface is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×