(1) Calculate F-(3) for a 600-keV electron. Calculate F+(8) for a 600-keV positron. (Marks 10) (2) Calculate the collisional stopping power of water for 600-keV electrons. Calculate the collisional stopping power of water for 600-keV positrons. (Marks 10) (3) What is the ratio of the collisional and radiative stopping powers of Al for electrons of energy (a) 10 keV (b) 1MeV (c) 100 MeV? (Marks 9) (4) Estimate the radiation yield for 10-MeV electrons in (a) Al