For an N channel JFET, a negative voltage at the gate typically causes what change in resistance?

In an N channel JFET (Junction Field Effect Transistor), applying a negative voltage to the gate leads to an increase in resistance. This behavior is rooted in the operation of the JFET, which is controlled by electric fields generated from the gate and channel interactions.

When a negative voltage is applied to the gate, it creates an electric field that attracts charge carriers (electrons in the case of an N channel) away from the channel region where conduction takes place. This effectively narrows the channel area by depleting it of carriers, thus hindering the flow of current through the device. As a result, the drain-source resistance increases.

This relationship between gate voltage and channel depletion is crucial for controlling the conductivity of the device. By manipulating the gate voltage, one can control the resistance and subsequently the current flowing from the drain to the source.