Advertisements
Advertisements
प्रश्न
Why is a cathode ray tube evacuated to a low pressure?
Advertisements
उत्तर
The cathode ray tube is evacuated to a low pressure to avoid collisions of electrons with air molecules.
APPEARS IN
संबंधित प्रश्न
Why do Free electrons not leave the metal surface on their own
What happens if the negative potential is changed on a grid?
Name a gas caused by the Greenhouse effect
In a cathode ray tube state:
(i) the purpose of covering cathode by thorium and carbon.
(ii) the purpose of the fluorescent screen.
(iii) how is it possible to increase the rate of emission of electrons.
An element P disintegrates by α - -emission and the new element suffers two further disintegrations, both by β -emission, to form an element Q. Explain the fact that P and Q are the isotopes.
Define free electrons.
State two characteristics of the substance used as thermionic emitter.
In a cathode ray tube state the purpose of the fluorescent screen.
An electrons emitter must have how much work function and melting point.
Two radioactive sources A and B of half lives of 1 hour and 2 hours, respectively, initially contain the same number of radioactive atoms. At the end of two hours, their rates of disintegration are in the ratio of ______.
