Why BJT is voltage controlled device?

Why BJT is voltage controlled device?

Question: Why BJT is known as current controlled device and FET is known as voltage controlled device? Answer: In BJT, output current depends on input current , so current controlled device. In FET, output current depends on input voltage, so voltage controlled device.

Why BJT is called controllable switch?

A BJT is a current controlled device because its output characteristics are determined by the input current. A FET is voltage controlled device because its output characteristics are determined by the Field which depends on Voltage applied.

How can the BJT be considered as a current controlled current source?

BJT is a current controlled device because the output characteristics of BJT are determined by the input current. In a p-n junction i.e base-emitter junction in BJT the change in voltage (Vbe) is produced only after the change in base current.

Where are BJT used?

The main basic function of a BJT is to amplify current it will allow BJTs are used as amplifiers or switches to produce wide applicability in electronic equipment include mobile phones, industrial control, television, and radio transmitters. There are two different types of BJTs are available, they are NPN and PNP.

Is BJT voltage controlled or current controlled?

Is BJT voltage controlled?

A physicist might say that the fundamental action in a BJT is that an electric field across the base-emitter junction decreases the width of the depletion zone. It is this electric field, measured in volts, that controls the movement of charge carriers. Therefore the BJT is voltage controlled.

How does a BJT operate?

How does BJT Work? For an NPN transistor, it consists of a layer of P-doped semiconductor between two layers of N-doped material, where electrons are passed from the emitter to the collector instead. The emitter then “emits” electrons into the base, with the base controlling the no. of electrons the emitter emits.

What is BJT why it is used?