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प्रश्न
State three ways of obtaining an electron-beam.
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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 are free electrons?
Radiations given out from a source when subjected to an electric field in a direction perpendicular to their path are shown below in the diagram. The arrows show the path of the radiation A, B and C. Answer the following questions in terms of A, B and C.
1) Name the radiation B which is unaffected by the electrostatic field.
2) Why does the radiation C deflect more than A?
3) Which among the three causes the least biological damage externally.
4) Name the radiation which is used in carbon dating.
What do you mean by Atomic mass?
What happens to the atomic number of element when (i) An α -particle, (ii) A β -particle 1 and (iii) γ-radiation is emitted?
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.
A radioactive nuclide `""_86^226` Ra decays by emission of two alpha particles, one beta particle and gamma rays. Which of the following is the resulting nuclide X?
What are the uses of radioactive isotopes in following?
(a) Medical field,
(b) Agriculture,
(c) Industries?
State two characteristics of the substance used as thermionic emitter.
Name the three main parts of a Cathode Ray Tube.
Mention four properties of Becquerel rays.
