GATE EC BJT and MOSFET Amplifiers questions

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

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 magnitude of the loop current (in amperes, correct to three decimal places) $0.5$ second after closing the switch 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 …

A good transconductance amplifier should have

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

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 …

For the circuit shown, assume that the NMOS transistor is in saturation. Its threshold voltage $V_{tn}=1V$ and its transconductance parameter $\mu_{n}C_{ox}\big(\frac{W}{L}\big)=1 \: mA/V^{2}$.Neglect channel length modulation and body bias effects. Under these conditions, the drain current $I_{D}$ in $mA$ is ________.

For the DC analysis of the Common-Emitter amplifier shown, neglect the base current and assume that the emitter and collector currents are equal. Given that $V_{T}=25mV,V_{BE}=0.7V$, and the BJT output resistance $r_{o}$ is practically infinite. Under these conditions, the midband voltage gain magnitude, $A_{v}=\mid v_{o}/v_{i} \mid$, V/V is …

An $npn$ bipolar junction transistor (BJT) is operating in the active region. If the reverse bias across the base-collector junction is increased, then

Consider the circuit shown in the figure. Assume base-to-emitter voltage $V_{BE}=0.8 V$ and common-base current gain ($\alpha$) of the transistor is unity. The value of the collector-to-emitter voltage $V_{CE}$ (in volt) is ____________

Two n-channel MOSFETs, T1 and T2, are identical in all respects except that the width of T2 is double that of T1. Both the transistors are biased in the saturation region of operation, but the gate overdrive voltage ($V_{GS}-V_{TH}$) of T2 is double that of T1,where $V_{GS}$ and $V_{TH}$ are the gate-to-source voltage and threshold voltage of the …

Assuming that transistors $M_1$ and $M_2$ are identical and have a threshold voltage of $1$ V, the state of transistors $M_1$ and $M_2$ are respectively

In the circuit shown, transistors $Q_1$ and $Q_2$ are biased at a collector current of $2.6$ mA. Assuming that transistor current gains are sufficiently large to assume collector current equal to emitter current and thermal voltage of $26$ mV, the magnitude of voltage gain $V_0/V_s$ in the mid-band frequency range is __________(up to second decimal …

What is the voltage $V_{out}$ in the following circuit ?

In the circuit shown in the figure, the maximum power (in watt) delivered to the resistor $R$ is _______