Voltage or volts is a force that moves the electrons, forcing a current. It can be compared to a water tank elevated at certain height or potential. If the water tank is placed low or low voltage the water wont flow quickly or low current. And if the tank is placed at a higher location or higher voltage the water will flow fast or high current.
The current or Ampere is a measurement of how many electrons flow through the device. In the analogy of water tank, the current is the water flow rate.
The resistance or Ohms slows down the current flow, the higher the circuit’s resistance, the lower the current will be. Resistance is equivalent to pipe size. If you put the water tank at a high level, but the pipe is very small in diameter or high resistance, there wont be much water flow. But if you use a big pipe or low resistance, the water flow rate will be bigger.
If you know the connection between voltage, current and resistance, you’ll learn about Ohm’s law: “current is proportional to Voltage divided by Resistance”. You can manipulate the equation to obtain any value knowing the other two. Here’s an example, by measuring the voltage and the current of a circuit, resistance can be calculated by dividing voltage by current. When a circuit is open or disconnected, the resistance is infinite or zero current. When a circuit is shorted the formula will also shows what happen or the resistance equal to zero: the battery will put out as much current as it can in a short time period.
