"Ohms Law: Ohm's Law is given by V = IR, where I is the current,V is the potential difference measured across the resistance and R is the resistance of the conductor in Ohms. A resistor is like a water wheel: it slows down the flow of water but turns it into work (heat). A battery is like a pump. It moves water uphill to a certain elevation (voltage). Likewise, a voltage drop is like a drop in elevation."