The beam current in a television tube is 32mA. The electrons travel at a speed of 4.2x10^7m/s through a distance 21cm. a) The number of electrons striking the screen in 1 hour is? I did: Q=IT = 0.032A x (60x60)s = 115.2 C Number of electrons = 115.2/1.6x10^-19 = 7.2x10^20 b) The number of electrons in the beam at any instant is? I tried doing the same as above but for one seconds but couldn't work it out at all. Anyone give me a clue?