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.
APPEARS IN
संबंधित प्रश्न
Under which conditions does the nucleus of an atom tend to radioactive?
What are the types of emission?
Justify with reason, whether the following nuclear reactions are allowed or not.
\[\ce{^A_Z X -> ^A_{Z + 1}Y + ^0_{-1}β}\]
Justify with reason, whether the following nuclear reactions are allowed or not.
\[\ce{^A_Z X -> ^A_{Z - 2}X + ^4_{2}He}\]
Two radioactive nuclei are represented by xAp and yAq and when p and q are mass numbers and x, y are the atomic number. How can the products be represented, i .e., what are the new values of p, q. x and y after the emission of an α-particle and a β-particle from A and B respectively.
From α, β and γ-rays, name the one which travels with the speed of light?
Explain, why radium paint, consisting of zinc sulphide and a trace of radium salt, glows in the dark?
The count rate of activity of a radioactive sample of a very large population decreased from 1024 to 128 in 3 minutes. Then the rate of disintegration at the end of 5 minutes is ______.
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)
