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
What is thermionic emission?
What are isobars?
An electromagnetic radiation is used for photography in fog. [2]
(i) Identify the radiation.
(ii) Why is this radiation mentioned by you, ideal for this purpose ?
What are the uses of radioactive isotopes in following?
(a) Medical field,
(b) Agriculture,
(c) Industries?
What do you mean by electron emission?
How is a cathode ray beam affected while passing through an electric field?
What are ‘Becquerel rays’?
Mention one important function of ear main parts:
State the principle on which the functioning of a nuclear reactor is based.
In U238 ore containing Uranium the ratio of U234 to Pb206 nuclei is 3. Assuming that all the lead present in the ore is final stable product of U238. Half life of U238 to be 4.5 × 109 years and the age of ore is ______ × 109 years. (in 109 years)
Calculate the time interval between 33% decay and 67% decay if half-life of a substance is 20 minutes.
