# What is the base of NPN transistor?

## What is the base of NPN transistor?

An NPN transistor is the most commonly used bipolar junction transistor, and is constructed by sandwiching a P-type semiconductor between two N-type semiconductors. An NPN transistor has three terminals– a collector, emitter and base. The NPN transistor behaves like two PN junctions diodes connected back to back.

How does current flow through NPN transistor?

In an NPN transistor, the flow of current runs from the collector terminal to the emitter terminal. In the PNP transistor, the flow of current runs from the emitter terminal to the collector terminal. As a result, a PNP transistor switches ON by a low signal, where an NPN transistor switches ON by a high signal.

Where is the base of an NPN transistor connected?

The npn transistor has three terminals: emitter, base and collector. The emitter terminal is connected to the left side n-type layer. The collector terminal is connected to the right side n-type layer. The base terminal is connected to the p-type layer.

### How do you find the base current of a PNP transistor?

PNP Transistor Example Base current, IB = VB/ RB = 1.5/ (200*103) = 7.5uA. Emitter current, IE = VE/ RE = (10-2)/ (5*103) = 8/ (5*103) = 1.6mA.

What is the formula of base current?

A bipolar NPN transistor has a DC current gain, (Beta) value of 200. Calculate the base current Ib required to switch a resistive load of 4mA. Therefore, β = 200, Ic = 4mA and Ib = 20µA. One other point to remember about Bipolar NPN Transistors.

What are the functions of a NPN transistor?

Applications of NPN transistor As NPN transistors are used for signal amplification. Thus used in amplifying circuits. It also finds its applications in logarithmic converters. One of the major advantages of NPN transistor is its switching characteristic. Thus widely used in switching applications. These are also used in high-frequency applications.

## What is the purpose of a NPN transistor?

Another common application for NPN transistors is to use them as an amplifier, in which a small increase in the input voltage induces a large change in the output voltage. NPN transistors are used for this purpose in almost all phones electronic devices in which sound amplification or reproduction is required.

What does a NPN transistor do?

NPN transistors have a positive layer located in-between two negative layers. Transistors are typically used in circuits for amplifying or switching electrical signals that pass through them. Both NPN and PNP transistors contain three leads, which are small metal pieces that connect the transistor to the circuit board.

Why is NPN transistor prefered over PNP?

When the transistors are used in electronic circuits for switching purpose, then the NPN transistor is more preferable than the PNP transistor because the switching speed of the NPN transistor is greater than the PNP transistor .