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Voltage is applied between the collector and emitter. A signal is applied between the base and emitter. The input signal will control how much the transistor turns on and the larger current flowing across the Collector/Emitter will be the same, but larger, than the input. Therefore amplified.
To keep the transistor switched on and to prevent the input signal switching it off, the transistor has to be biased on. This is usually done with a network of resistors on the base, raising the voltage to keep it conducting.
In forward active mode, transistor can amplify current and/or voltage signals. So here, it can be used as an amplifier.
To understand this read as follows...
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 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.
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When transistor acts as an amplifier then does its output voltage increase or decrease?
That depends on both the input signal and the type of amplifier the transistor is used in.
Why is it necessary to bias a transistor when it is to be used as an amplifier?
Biasing is necessary in a transistor circuit to keep the transistor working. Without proper biasing, the circuit will fail
Why the gain of pnp transistor is low?
it doesn't have to be. depends on design of amplifier using transistor.
What is meant by external gain of amplifier?
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..................
What is the function of resistor in single stage amplifier?
A simple, 1 transistor single stage amplifier can be made using several resistors to bias a NPN or PNP transistor into its' linear operating region. With this done, a small voltage signal applied to the input of the amplifier will have the voltage amplified at the output in a linear fashion. I'm not sure what your question is; if this does not answer it let me know.
How transistor acts as a amplifier?
A transistor does not act as an amplifier. It is used as a component in an amplifier circuit.
When a PNP transistor is connected in a circuit it can be used as a power amplifier because?
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.
What component is typically used as an amplifier?
A transistor
When transistor acts as an amplifier then does its output voltage increase or decrease?
That depends on both the input signal and the type of amplifier the transistor is used in.
Why a transistor is used as a amplifier and switch?
transistor has 2 output 1 and 0 so can be used as a switch
Why is it necessary to bias a transistor when it is to be used as an amplifier?
Biasing is necessary in a transistor circuit to keep the transistor working. Without proper biasing, the circuit will fail
What is difference between transistor and amplifier?
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).
How does transistor acts as an amplifier?
When transformer is used in step up mode then we can use transformer as amplifire
How does transistor acts an amplifier?
When transformer is used in step up mode then we can use transformer as amplifire
Which bjt transistor amplifier can be used as a voltage buffer?
the common collector can use as voltage buffer
What is internal gain of amplifier?
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..................
Is transistor a current amplifier or voltage amplifier?
depends on the circuit it is used in:CE/CS is inverting voltage amplifierCC/CD is noninverting current amplifierCB/CG is noninverting voltage amplifier
