// Additional solved numerical questions  , Example(set 3) 11_a , pg 355
Un=3*10^-3    //electron mobility   (in m^2/(V*s))
e=1.6*10^-19    //charge in electron   (in C)
Me=9.11*10^-31     //mass of electron   (in Kg)
T=(Me*Un)/e    //mean free time
printf("Mean free time(in S)")
disp(T)