The Bridge

In order for a stationary car to cross a river, it would need a bridge. But having the bridge alone is not enough. Without someone driving the car or a force being applied to it, it will remain there.

Imagine this as your MOSFET. Having the channel alone (or the bridge) is not enough. In order for electrons to flow, you need a potential difference. Going back to the brige example, if one end of the bridge is being tilted up, the car would move even without someone driving it.  You got that right, there is a difference in potential.

This is the reason why, a potential difference needs to be applied across drain and source so that electrons can flow through the channel. You can do this by having a power supply or a battery between the drain and source - where source in connected to GND.

We'll see in the next writing how a MOSFET is being connected in a circuit. You will see clearly a connectiom between drain and soruce is done.

Titan - The Mars Moon