A transistor acts like a valve or gate that opens and closes, and allows a current to flow. Since the amount of current that flows is controlled by another input, they can be used to make amplifiers. Carbon microphones and vacuum tubes have the same property, and so have also been used to make amplifiers historically.
A transistor doesn't have any mechanical parts to wear out, so it will last longer. A transistor can switch much faster than a mechanical device, so they can switch all the way from DC up into the microwave region. It is physically small. Very handy. It allows a relatively small controlling current to switch very large controlled currents.
Transistors are semiconductor devices that can be made very small as part of integrated circuits or can be individual devices. They can act as amplifiers and switches so they are useful in may applications in both digital and analog circuits. They come in many types suitable for different types of applications.
The question should be like: How can a transistor be used as an amplifier...??
Answer:
There are four mode of operations for a transisitor.
1. Forward active mode.
2. Reverse active mode.
3. Cut Off mode.
4. Saturation Mode.
To be an amplifier, transistor must be used in forward active mode.
To understand the modes, lets consider a pnp/npn transistor. In forward active mode, Emitter-Base Junction is forward biased & Collectror-Base Junction is reverse Biased.
In Reverse active mode, Emitter-Base Junction is reverse biased & Collector Base junction is forward biased.
In Cut off mode, both the junctions are reverse biased.
In Satuiration mode, both the junctions are forward biased.
A PNP transistor has no advantage or disadvantage over an NPN transistor in its ability as an amplifier. Rather, the current-handling capacities of the transistor determine if it's usable as an amplifier.
output current is zero
Voltage amplifier
A transistor
single stage amplifier contain only one stage transistor amplifier but multi stage contain more than one amplifier stage
A transistor does not act as an amplifier. It is used as a component in an amplifier circuit.
A PNP transistor has no advantage or disadvantage over an NPN transistor in its ability as an amplifier. Rather, the current-handling capacities of the transistor determine if it's usable as an amplifier.
A transistor
That depends on both the input signal and the type of amplifier the transistor is used in.
transistor has 2 output 1 and 0 so can be used as a switch
Biasing is necessary in a transistor circuit to keep the transistor working. Without proper biasing, the circuit will fail
A transistor is an electronic component. By itself it has little use. An amplifier is a complete, functional circuit, generally made up of several components. A transistor can be a component part of an amplifier, however an amplifier may be constructed without any transistors (using vacuum tubes instead, for instance).
When transformer is used in step up mode then we can use transformer as amplifire
When transformer is used in step up mode then we can use transformer as amplifire
the common collector can use as voltage buffer
The internal gain of an amplifier is the gain or the amplification factor of the transistor used in it....................it is internal because it is fixed for transistors while manufacturing..................
depends on the circuit it is used in:CE/CS is inverting voltage amplifierCC/CD is noninverting current amplifierCB/CG is noninverting voltage amplifier