Questions: 19. A JFET always operates with (a) the gate-to-source pn junction reverse-biased (b) the gate-to-source pn junction forward-biased (c) the drain connected to ground (d) the gate connected to the source

Solution Steps

A Junction Field Effect Transistor (JFET) is a type of transistor that controls current flow using an electric field. It has three terminals: the gate, the source, and the drain. The JFET operates by varying the voltage applied to the gate terminal, which in turn controls the current flowing from the source to the drain.

In a JFET, the gate-to-source junction is typically a pn junction. For the JFET to function properly, this junction must be reverse-biased. This means that the gate is at a lower potential than the source for an n-channel JFET, or at a higher potential for a p-channel JFET. Reverse-biasing the gate-to-source junction ensures that the gate current is minimal, allowing the JFET to control the drain current effectively.

Let's evaluate the given options:

• (a) The gate-to-source pn junction reverse-biased: This is correct, as the JFET operates with the gate-to-source junction reverse-biased to control the current flow.
• (b) The gate-to-source pn junction forward-biased: This is incorrect, as forward-biasing would allow significant current to flow through the gate, which is not desired in JFET operation.
• (c) The drain connected to ground: This is not a requirement for JFET operation.
• (d) The gate connected to the source: This is incorrect, as it would not allow for control of the current flow.

Final Answer