In a computer monitor, an electron beam with a current of 4x10^-6 A is directed at the screen. How many electrons are transferred to the monitor in 2 minutes.

I= Δq/Δt =N•e/ Δt.

N = I•Δt/e = =4•10^-6•2•60/1.6•10^-19=
=3•10^15