I learnt in one of my classes that “current flows in the path of least resistance” but how does the current know which path is least resistant?
In: 5
Current doesn’t “know” anything.
What happens is that charges have different potential energy at different points in a circuit. Let’s say there is a potential energy difference at point A and point B. The energy difference per unit charge is referred to voltage (V) across A and B.
In a circuit, what we find is that the current (I – in units of amount of charge per unit time flowing through) between A and B is proportional to the voltage. This proportionality is given by V = I * R where R is called the resistance between A and B (note: this is a simplification because there’s also something called reactance, but this is a whole other discussion). Just like a ball having higher potential energy at the top of a slope compared to the bottom, current flows from high potential to low potential.
Higher resistance with the same voltage means lower current and vice versa.
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