GATE EC Analog Circuits questions

A circuit with an ideal $\text{OPAMP}$ is shown in the figure. A pulse $V_{\text{IN}}$ of $20\:ms$ duration is applied to the input. The capacitors are initially uncharged. The output voltage $V_{\text{OUT}}$ of this circuit at $t=0^{+}$ (in integer) is ____________________ $V$.

In the circuit shown below, all the components are ideal. If $V_{i}$ is $+2\:V$, the current $I_{o}$ sourced by the op-amp is __________ $\text{mA}$.

The base of an $\text{npn BJT T1}$ has a linear doping profile $N_{B}\left ( x \right )$ as shown below. The base of another $\text{npn BJT T2}$ has a uniform doping $N_{B}$ of $10^{17}cm^{-3}$. All other parameters are identical for both the devices. Assuming that the hole density profile is the same as that of doping, the common-emitter current …

For the $\text{BJT}$ in the amplifier shown below, $V_{BE}=0.7V,\:kT/q=26\:mV$. Assume that $\text{BJT}$ output resistance $(r_{o})$ is very high and the base current is negligible. The capacitors are also assumed to be short circuited at signal frequencies. The input $v_{i}$ is direct coupled. The low frequency voltage gain $v_{o}/v_{i}$ of the …

In the voltage regulator shown below, $V_{1}$ is the unregulated imput at $15\:V$. Assume $V_{BE}=0.7\:V$ and the base current is negligible for both the $\text{BJTs}$. If the regulated output $V_{O}$ is $9\:V$, the value of $R_{2}$ is ___________$\Omega$

In the circuits shown the threshold voltage of each $\text{nMOS}$ transistor is $0.6\:V.$ Ignoring the effect of channel length modulation and body bias. the values of $\text{Vout}1$ and $\text{Vout} 2,$ respectively, in volts, are

A $2\times 2$ ROM array is built with the help of diodes as shown in the circuit below. Here $W0$ and $W1$ are signals that select the word lines and $B0$ and $B1$ are signals that are output of the sense amps based on the stored data corresponding to the bit lines during the read operation. …

The distance (in meters) a wave has to propagate in a medium having a skin depth of $0.1\:m$ so that the amplitude of the wave attenuates by $20\:dB$, is

For the circuit given in the figure, the voltage $V_{c}$ (in volts) across the capacitor is

For the circuit given in the figure, the magnitude of the loop current (in amperes, correct to three decimal places) $0.5$ second after closing the switch is _______.

A $dc$ current of $26\:\mu A$ flows through the circuit shown. The diode in the circuit is forward biased and it has an ideality factor of one. At the quiescent point, the diode has a junction capacitance of $0.5\:nF$. Its neutral region resistances can be neglected. Assume that the room temperature thermal equivalent voltage is $26\:mV$. For …

An op-amp based circuit is implemented as shown below. In the above circuit, assume the op-amp to be ideal. The voltage (in volts, correct to one decimal place) at node $A$, connected to the negative input of the op-amp as indicated in the figure is ________.

In the circuit shown below, the $(W/L)$ value for $M_{2}$ is twice that for $M_{1}$. The two $\text{nMOS}$ transistors are otherwise identical. The threshold voltage $V_{T}$ for both transistors is $1.0\:V$. Note that $V_{GS}$ for $M_{2}$ must be $> 1.0\:V$. Current through the $\text{nMOS}$ transistors can be modeled as …

For a narrow base PNP BJT , the excess minority carrier concentrations($\Delta n_{E}$ for emitter,$\Delta p_{B}$ for base ,$\Delta n_{c}$ for collector) normalized to equilibrium minority carrier concentrations($n_{E0}$ for emitter, , $\Delta p_{B0}$ for base ,$\Delta n_{C0}$ for collector) in the quasi-neutral emitter,base and collector regions …

For the operational amplifier circuit shown, the output saturation voltage are $\pm 15 \:V$. The upper and lower threshold voltages for the circuit are,respectively,

A good transconductance amplifier should have

The Miller effect in the context of a Common Emitter amplifier explains

Which of the following can be the pole-zero configuration of a phase-lag controller (lag compensator)?

In the circuit shown, the voltage $V_{IN}(t)$ is described by: $$V_{IN}(t)=\begin{cases} 0, & \text{for } t< 0 \\ 15 \text{Volts} & \text{for } t\geq 0 \end{cases}$$ where $t$ is in seconds. The time (in seconds) at which the current $I$ in the circuit will reach the value $2$ Amperes is ___________.

In the figure shown, the $npn$ transistor acts as a switch. For the input $V_{in}(t)$ as shown in the figure, the transistor switches between the cut-off and saturation regions of operation, when $T$ is large. Assume collector-to-emitter voltage at saturation $V_{CE(sat)}=0.2V$ and base-to-emitter voltage $V_{BE}=0.7V$.The minimum value of the …