given that tube is operated for t = 25 ms
which means the time for which it is used is t = 0.025 s
now the photons generated is given as
[tex]N = 2.5 * 10^{14}[/tex]
each photon will produce 1 electron as we can assume it to be 100% efficient
so number of electrons per second will be same as number of photons per second
now in order to find the current we can say
current = rate of flow of charge
[tex]i = \frac{dN}{dt}*e[/tex]
[tex]i = \frac{2.5 * 10^{14}}{0.025}* 1.6 * 10^{-19}[/tex]
[tex]i = 1.6 * 10^{-3} A[/tex]
so the current in the tube for given time will be 1.6 mA
