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It can be answered in two ways :
1. ratio of output & input voltages [Vout / Vin] i.e Drain voltage(Vds)/Source voltage(Vs).
2. multiplication of trans-conductance & drain resistance .
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What is voltage gain?
Voltage gain is the ratio of the output voltage of an amplifier to its input voltage.
Why does amplifier gain reduce?
Since we know that the amplifier gain is given by A=Output voltage/input voltage (where A is the amplifier gain) So, it can be written as output voltage=A*input voltage, so when the output part increases gain increases but when input part increases gain decreases
Does the power amplifier amplifies the power?
the final stage of a power amp is a current amplifier in a bipolar design and a voltage amp in a FET design.
Advantages of common source fet amplifier?
Due to high input impedence curret gain is high
What is the effect of Rs and RL on the voltage gain of an amplifier?
it reduces the gain
Why the voltage gain of an FET amplifier is generally less than that obtained using BJT amplifier?
A FET (Field Effect Transistor) is mainly used when the input signal needs to be isolated from the output. A FET has a very high input resistance, so very little current is required from the input. Voltage gain is not the main objective when using a FET.
The voltage gran of an amplifier is 200 The decibel voltage gain is?
The voltage gain of an amplifier is 200. The decibel voltage gain is? Answer Gain in dB = 20 * log 200 = 46 dB
What is voltage gain?
Voltage gain is the ratio of the output voltage of an amplifier to its input voltage.
Why does amplifier gain reduce?
Since we know that the amplifier gain is given by A=Output voltage/input voltage (where A is the amplifier gain) So, it can be written as output voltage=A*input voltage, so when the output part increases gain increases but when input part increases gain decreases
Does the power amplifier amplifies the power?
the final stage of a power amp is a current amplifier in a bipolar design and a voltage amp in a FET design.
What is use of voltage amplifier?
obtaining voltage gain of a weak signal
Advantages of common source fet amplifier?
Due to high input impedence curret gain is high
What is the effect of Rs and RL on the voltage gain of an amplifier?
it reduces the gain
How does a voltage controlled amplifier work?
A Voltage Controlled Amplifier or VCA is a device whose gain is set by the voltage level of a control signal.
What is input impedance of fet amplifier?
Zin=Vds/Id [Vds=drain to source voltage ; Id = drain current]
How can transistors act as amplifiers?
The small signal model for the common source FET can be used for analysing the basic FET amplifierconfigurations:(i)common source(CS),(ii)commondrain(CD) or source follower,and(iii)common gate(CG). The CS amplifier which provides good voltage amplification is most frequentlyused.The CD amplifier with high input impedance andnear-unity voltage gain is used as a buffer amplifier and the CG amplifier is used as a high frequencyamplifier.The small signal current-sourcemodel for the FET in CS configuration and the voltage source model can be derived by finding the Thevenin'sequivalent for the output part of amplificationfactor,drain resistance andtransconductance/mutual conductance of the FET.
What is voltage follower?
A voltage buffer amplifier is used to transfer a voltage from a first circuit, having a high output impedance level, to a second circuit with a low input impedance level.If the voltage is transferred unchanged (the voltage gain Av is 1), the amplifier is a unity gain buffer; also known as a voltage follower because the output voltage follows or tracks the input voltage. Although the voltage gain of a voltage buffer amplifier may be (approximately) unity, it usually provides considerable current gain and thus power gain
