what is the magnitude of the the least possible current that could theoretically exist?

Answer 1

Current is rate defined as charge (Q, coulombs) per unit time (seconds). A single elementary charge is equal to 1.60217653 × 10 ^ -19 coulombs, but you still need to specify the amount of time. If you use 1 charge in 1 second, then it is simply 1.60217653 × 10 ^ -19 Amps. Make it a longer time, and you'll get a smaller current.

Answer 2

current is the measure of charge over time. no current is the least possible current.

a single electron trapped somewhere and never moving would be no current.

if the electron HAD to move, it could take all the time it wanted to - an electric potential on the order of picovolts would cause the single electron to move so slowly along its path, it would take an insane amount of time to go anywhere. so the denominator would be amazingly large making the current extremely close to 0.

Answer 3

Your question doesn't really make sense.

current is defined as coulombs per second, but coulobs are quantized by the electrical charge of an electron.

The smallest current, measureable in would then be a single electron per second, so 1.602 x 10^-19 coulombs/second (amps).

However, you can get smaller currents than that, such as 1 electron per minute or 1 electron per year, so I don't see how your question can be numerically answered.