The gain of a common emitter amplifier is given by `A_(V)=-g_(m)R_(L)`. Does it mean that if we keep on increasing indefinitely `R_(L)`, the gain of the amplifier will also increase indefinitely? Explain your answer.
Text Solution
Verified by Experts
The gain of the amplifier will not increase indefinitely on increasing `R_(L)` indefinitely. As `V_C=V_(CE)-I_C R_(L)` Therefore, as `R_(L)` increases, the value of `V_C` decreases. When the value of `V_C` becomes less than the base voltage, both the junction in transistor get forward biased. Due to it, the current becomes saturated. It means no further increase of current takes place and hence no further gain of the amplifier.
Topper's Solved these Questions
ELECTRONIC DEVICES
PRADEEP|Exercise SAMPLE PROBLEM|2 Videos
ELECTRONIC DEVICES
PRADEEP|Exercise CONCEPTUAL PROBLEMS|1 Videos
ELECTROMAGNETIC WAVES
PRADEEP|Exercise II Focus multiple choice question|5 Videos
ELECTROSTATICS
PRADEEP|Exercise ASSERTION-REASON TYPE QUESTIONS|2 Videos
Similar Questions
Explore conceptually related problems
Input signal to a common emitter amplifier having a voltage gain of 1000 is given by v_(1) = (0.004 V) sin(omega t + pi/2) . The corresponding output signal is
For a common emitter amplifier, input resistance (R_i) = 500Omega and load resistance R_L = 5000Omega . If beta = 60, then the voltage gain is
Power gain of transistor amplifier with common base circuit or common emitter circuit is large. Does it mean the power is generated by the transistor? Explain.
In a common base transistor amplifier if the input resistance R_(i) is 200 Omega and load resistance R_(L) is 20K Omega , find voltage gain (alpha=0.95)
In a common emitter amplifier, using output reisistance of 5000 ohm and input resistance fo 2000 ohm, if the peak value of input signal voltage is 10 m V and beta=50 . The power gain is
In each of the following questions, some letters are given. Arrange the letters properly to make a meaningful word and indicate the index of the letter, i.e., (a), (b), (c ) or (d) that you have chosen to put last in the word, as your answer. "m e t r i l a n"
A n-p-n transisitor is connected in common emitter configuration in a given amplifier. A load resistance of 800 Omega is connected in the collector circuit and the voltage drop across it is 0.8 V . If the current amplification factor is 0.96 and the input resistance of the circuits is 192 Omega , the voltage gain and the power gain of the amplifier will respectively be
In a common -emitter transistor amplifier, an increase of 50muA in the base current causes an increase of 1.0mA in the collector current . Calculat gain beta . What will be the change in emitter current? Also calculate current gain alpha
