GATE EC Analog Circuits questions

The ideal $\text{OP-AMP}$ circuit shown in the Figure produces output voltage $V_{o}=x$ when the Switch, $\text{S}$, is open. Which of the options represents the output voltage when $\text{S}$ is closed?

A circuit using an ideal $\text{OP-AMP}$ is shown in the Figure. Which of the following options gives the correct value of the current $I_{X}$?

Consider an ideal OP-AMP circuit as shown in the Figure. The resistances $R_{1}=R_{2}=R_{3}=R_{4}=50 \mathrm{~k} \Omega$. The magnitude of the closed loop gain is $\_\_\_\_$ . (rounded off to two decimal places)

Consider the ideal diodes $\text{D1}$ and $\text{D2}$ as shown in the Figure with cut-in voltage $V_{\gamma}=0$ Volt and $v_{i}(t)$ is in Volt. The maximum voltage (Volt) of the output $v_{o}(t)$ is $\_\_\_\_$ . (rounded off to two decimal places)

A simplified small-signal equivalent circuit of a BJT-based amplifier is given below. The small-signal voltage gain $V_{o} / V_{S}$ (in $\mathrm{V} / \mathrm{V})$ is $\_\_\_\_\_\_$

The ideal BJT in the circuit given below is biased in the active region with a $\beta$ of $100$. If $I_{B}$ is $10 \: \mu \mathrm{A}$, then $V_{C E}$ (in Volts, rounded off to two decimal places) is $\_\_\_\_\_\_\_\_$.

Which of the following statements is/are TRUE with respect to an ideal opamp?

Which of the following statements is/are TRUE with respect to ideal MOSFET-based DC-coupled single-stage amplifiers having finite load resistors?

The identical MOSFETs $M_{1}$ and $M_{2}$ in the circuit given below are ideal and biased in the saturation region. $\mathrm{M}_{1}$ and $\mathrm{M}_{2}$ have a transconductance $g_{m}$ of $5$ mS. The input signals (in Volts) are: $$\begin{array}{l} V_{1}=2.5+0.01 \sin \omega t \\ V_{2}=2.5-0.01 \sin \omega t \end{array}$$ The output signal …

In the circuit shown, the identical transistors $\text{Q1}$ and $\text{Q2}$ are biased in the active region with $\beta=120$. The Zener diode is in the breakdown region with $\mathrm{V}_{\mathrm{Z}}=5 \mathrm{~V}$ and $\mathrm{I}_{\mathrm{Z}}=25 \mathrm{~mA}$. If $\mathrm{I}_{\mathrm{L}}=12 \mathrm{~mA}$ and …

All the diodes in the circuit given below are ideal. Which of the following plots is/are correct when $V_{I}$ (in Volts) is swept from $-M$ to $M$?

The diode in the circuit shown below is ideal. The input voltage (in Volts) is given by $V_{I}=10 \sin 100 \pi t$, where time $t$ is in seconds. The time duration (in $\mathrm{ms}$, rounded off to two decimal places) for which the diode is forward biased during one period of the input is $\_\_\_\_$

An ideal p-n junction germanium diode has a reverse saturation current of $10 \mu \mathrm{~A}$ at $300 \: \mathrm{ K}$. The voltage (in Volts, rounded off to two decimal places) to be applied across the junction to get a forward bias current of $100 \: \mathrm{mA}$ at $300 \: \mathrm{K}$ is $\_\_\_\_\_\_\_$. (Consider the Boltzmann constant …

​​​​In the circuit below, assume that the long channel $\text{NMOS}$ transistor is biased in saturation. The small signal trans-conductance of the transistor is $g_{m}$. Neglect body effect, channel length modulation and intrinsic device capacitances. The small signal input impedance $Z_{i n}(j \omega)$ is $\_\_\_\_\_\_$

​​​​For the closed loop amplifier circuit shown below, the magnitude of open loop low frequency small signal voltage gain is $40$. All the transistors are biased in saturation. The current source $I_{S S}$ is ideal. Neglect body effect, channel length modulation and intrinsic device capacitances. The closed loop low frequency small signal voltage gain …

​In the circuit shown, the $n: 1$ step-down transformer and the diodes are ideal. The diodes have no voltage drop in forward biased condition. If the input voltage (in Volts) is $V_{s}(t)=10 \sin \omega t$ and the average value of load voltage $V_{L}(t)$ (in Volts) is $2.5 / \pi$, the value of $n$ is $\_\_\_\_\_\_\_$.

In the given circuit, the current $I_{x}$ (in $m A$ ) is $\_\_\_\_\_\_\_\_$.

​​​​​The opamps in the circuit shown are ideal, but have saturation voltages of $\pm 10 \mathrm{~V}$. Assume that the initial inductor current is $0 \mathrm{~A}$. The input voltage $\left(\mathrm{V}_{\mathrm{i}}\right)$ is a triangular signal with peak voltages of $\pm 2 \mathrm{~V}$ and time period of $8 \mu \mathrm{s}$. Which one of the following …

In the circuit below, the opamp is ideal. If the circuit is to show sustained oscillations, the respective values of $R_{1}$ and the corresponding frequency of oscillation are

Which of the following statements is/are true for a $\text{BJT}$ with respect to its DC current gain $\beta$ ?