Advertisements
Advertisements
Question
Why are materials of low work function preferred as thermionic cathode materials?
Advertisements
Solution
By using materials of low work functions, the emission of electrons from such a surface takes place at relatively low temperature (at 1700°C in instead of 2500°C approximately).
RELATED QUESTIONS
Answer the following questions based on a hot cathode ray tube.
What will happen to the beam when it passes through the electric field?
Name a gas caused by the Greenhouse effect
A nucleus `""_11^24Na` emits a beta particle to change into Magnesium (Mg)
(i) Write the symbolic equation for the process.
(ii) What are numbers 24 and 11 called?
(iii) What is the general name of `""_12^24Mg `with respect to `""_11^24Na` ?
What happens to the position of an element in the periodic table when it emits an alpha particle
How is a cathode ray beam affected while passing through an electric field?
What are cathode rays? Why are they called ‘cathode rays’? Name a material which exhibits fluorescence when cathode rays fall on it.
Name the Different Radiations Which Are Emitted by the Radioactive Substances.
Are all the radiations mentioned by you, emitted in a single radioactive decay?
Which part of the atom undergoes a change in the process of radioactive decay?
A deuteron strikes 8O16 nucleus with subsequent emission of an alpha particle. Identify the nucleus so produced:
When an α-particle of mass m moving with velocity ν bombards on a heavy nucleus of charge Ze, its distance of closest approach from the nucleus depends on m as:
