JNTU B.Tech II Year ELECTRONIC CIRCUIT ANALYSIS Previous Question Paper (December - 2017 - R13)

Draw a small signal low frequency model of a transistor.

State dual of Miller’s theorem and also write its applications.

What is unity crossover frequency?

Define a short circuit gain of a transistor in CE configuration at high frequencies.

What is effect of negative feedback on amplifier gain?

State Barkhausen criterion of oscillator.

Why heat sinks are needed?

What is mean by crossover distortion?

Define Q factor of tuned amplifier.

What are the limitations of Single tuned amplifier?

The h parameters of a transistor used in single stage amplifier circuit are hie = 1100, hre =1, hfe=51 and hoe=25µA. Determine the amplifier parameters for CC configuration when RS=RL=10K.

For any single-stage amplifier express input resistance in terms of current gain and h-parameters only.

Derive the bandwidth of a multistage amplifier, assuming that each stage has same upper and lower cut off frequencies.

For the two stage amplifier of the figure 1, calculate the input and output impedance, and the individual and overall voltage gains. Assume hfe =50, hie=1.1kΩ, hre = hoe= 0.

A transistor biased at 20mA, 20V, it has the h-parameters at room temperature hie =500Ω, hfe=100, hre =10⁻⁴, hoe =4×10⁻⁵℧. It has fT =50MHz and CC=3pF. Find all the values of hybrid π components.

The 3-db bandwidth of an amplifier extends from 20 Hz to 20 kHz. Find the frequency range over which the voltage gain differs by only 1 dB from the mid band value.

The amplifier of figure 2 uses a FET with IDSS =3mA, Vp= -3V, rd>>Rd. Find the quiescent drain current, quiescent drain to source voltage and AV.

Derive the equation for voltage gain of a CS FET amplifier.

An amplifier has an open loop voltage gain of 1000 and delivers 10W output with 10% second harmonic distortion when the input is 10mV. Find the distortion if 60dB of negative feedback is applied.

Calculate Avf = V0/Vs, Rif and Rof for the circuit shown in figure 3 use typical h parameter values. Rs=RC=10K and Re=1K.

Derive an expression for frequency of oscillations of a RC phase shift oscillator using transistor.

A colpitts oscillator is designed with C1 = 100pF and C2=7500pF. Find the range of inductance values if the frequency of oscillations vary between 950 and 2050KHz.

Classify amplifiers based on operating point selection. Compare them in terms of efficiency and distortion.

A transformer coupled class A large signal amplifier has maximum and minimum values of collector-to-emitter voltage of 25V and 2.5V. Determine its collector efficiency.

What is push pull configuration and how does this circuit reduce the harmonic distortion?

Given an ideal class B Push Pull amplifier whose collector supply voltage is Vcc, and RL′ = n²RL are fixed as base current excitation is varied, show that the collector dissipation Pc is zero at no signal, rises as Vm increases and passes through a maximum at Vm=2Vcc/π.

How to reduce the instability in tuned amplifier? Explain them with neat circuit diagram.

What are the advantages of stagger tuned amplifier? Draw its frequency response.