Question

A beam of protons is moving toward a target in a particle accelerator. This beam constitutes a current whose value is 0.50 μA. How many protons strike the target in 15 seconds?

Answer 1

I = 5*10  - 7A

q = 5 *15*1-  - 7 cuolomb
= 75 *10 -7 C in 15 sec is indecent

1 proton has  q = 1.6 *10 - 19C

75 *10-7  / 16* 10-19

= 4.7 x 10^13

Hope this helps