Waec 2022 Physics Question 12

12a(i) What is meant by the term artificial radioactivity? (ii) Complete the table below. Emission Nature Charge Ionizing ability High speed electron Moderately ionizing Neutral Negligible ionizing ability Alpha particle Positive (b) In an X-ray tube, an electron is accelerated from rest towards a metal target by a \( 30 k V \) source. Calculate the kinetic energy of the electron. \( [e=1.6 \times 10^{-19} C] \). (c) The table below shows the frequencies of radiation incident on a certain metal and the corresponding kinetic energies of the photoelectrons. (ii) Plot a graph of kinetic energy, K.E., on the vertical axis and frequency, \( f \), on the horizontal axis starting both axes from the origin \( (0,0) \). (ii) From the graph, determine the I. Planck's constant; II. threshold frequency of radiations; III. work function of the metal.