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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
Answer the following questions based on a hot cathode ray tube
Name the charged particles
State three factors on which the rate of emission of electrons from a metal surface depends
State the energy conversion taking place in a cathode ray tube
Complete the diagram as given above by drawing the deflection of radioactive radiations in an electric field
State two similarities and two dissimilarities between the γ-rays and X-rays.
In a cathode ray tube state the purpose of covering cathode by thorium and carbon.
The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be ______.
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)
