Feedback Amplifiers and Oscillator Circuits · Analog Electronics · GATE EE

In the Wien Bridge oscillator circuit shown in figure, the bridge is balanced when

In the feedback network shown below, if the feedback factor $$k$$ is increased, then the

As shown in the figure, a negative feedback system has an amplifier of gain $$100$$ with $$ \pm 10\% $$ tolerance in the forward path, and an attenuator of value $$9/100$$ in the feedback path. The overall system gain is approximately.

An op-amp has an open-loop gain of $${10^5}$$ and an open-loop upper cutoff frequency of $$10$$ $$Hz.$$ If this op-amp is connected as an amplifier with a closed-loop gain of $$100,$$ then the new upper cutoff frequency is

A practical $$R$$-$$C$$ sinusoidal oscillator is built using a positive feedback amplifier with a closed loop gain slightly less than unity.

Given figure shows a two stage small signal transistor feedback amplifier. Match the defective component (listed on the left hand side below) with its probable effect on the circuit (listed below)

List - $${\rm I}$$
$$A.$$ Capacitor $${C_1}$$ is open
$$B.$$ Capacitor $${C_3}$$ is open
$$C.$$ Capacitor $${C_4}$$ is open
$$D.$$ $$R{C_2}$$ is shorted

List - $${\rm II}$$
$$P.$$ All $$dc$$ voltages normal, $${V_0}$$ increases marginally
$$Q.$$ Collector of $$T{R_2}$$ at $${V_{cc}},\,\,{V_0} = 0$$
$$R.$$ All $$dc$$ voltages normal, gain of $${2^{nd}}$$ stage decreases, $${V_0}$$ decreases.
$$S.$$ All $$dc$$ voltage normal, $${V_0} = 0$$
$$T.$$ All $$dc$$ voltages normal, overall gain of the amplifier increases, $${V_0}$$ increase
$$U.$$ No change

A Wein bridge oscillator is shown in figure. Which of the following statements are true if $$'f'$$ is the frequency of oscillation?

In a common Emitter amplifier, the un bypassed emitter resistance provides

The voltage series feedback in a feedback amplifier leads to

An oscillator circuit using ideal op-amp and diodes is shown in the figure.

The duration for $$+ve$$ part of the cycle $$\Delta {t_1}$$ and for $$-ve$$ part is $$\Delta {t_2}.$$ The value of $$e$$ $${{\Delta {t_2} - \Delta {t_1}} \over {RC}}$$ will be _______.

The circuit shown is a

Determine the transfer function $$\left( {{{{V_y}} \over {{V_x}}}} \right)$$ for the $$RC$$ network shown in figure $$(1).$$

The network is used as a feedback circuit in an oscillator circuit shown in figure $$(2)$$ to generate sinusoidal oscillations. Assuming that the operational amplifier is ideal, determine the value of $${R_F}$$ for generating these oscillations. Also determine the oscillation frequency if $$R = 10\,\,k\Omega $$ and $$C=100PF$$

Show that the circuit given in fig. will work as an oscillator at $$f = {1 \over {2\pi RC}},$$ if $${R_1} = 2{R_2}$$

Determine the frequency of Oscillation of the circuit shown in figure, Assume the OP-amp to be ideal