Advertisements
Advertisements
प्रश्न
State three ways of obtaining an electron-beam.
Advertisements
उत्तर
The three ways are:
(i) In a cathode ray tube, when pressure of 0.01 mm of Hg and a high p.d. of about 10000 V is applied across its electrodes.
(ii) In a diode-valve, it is produced from the heated cathode from where they are attracted by the anode plate kept at a high positive potential.
(iii) Electrons are also produced in the process known as ‘photo electric emission’ by focussing light on a metal surface coated with cesium oxide.
संबंधित प्रश्न
State three factors on which the rate of emission of electrons from a metal surface depends
A radioactive source emits three types of radiations. Name them.
(i) Name the radiations which are charged.
(ii) Name the radiations which are most penetrating.
(iii) Name the radiations which travel with the speed of light.
(iv) Name the radiations which have the largest mass.
Why should a radioactive substance not be touched by hands?
What do you mean by electron emission?
What are cathode rays? Why are they called ‘cathode rays’? Name a material which exhibits fluorescence when cathode rays fall on it.
State any two uses of cathode rays.
What are ‘Becquerel rays’?
Mention four properties of Becquerel rays.
88Ra226 experiences three α - decay. Find the number of neutrons in the daughter element.
