GATE EC question library

Let $U$ and $V$ be two independent zero mean Gaussian random variables of variances $\dfrac{1}{4}$ and $\dfrac{1}{9}$ respectively. The probability $P(3V\geq 2U)$ is

Let $A$ be an $m \times n$ matrix and $B$ an $n \times m$ matrix. It is given that determinant $(I_{m} + AB) =$ determinant $(I_{n} + BA),$ where $I_{k}$ is the $k \times k$ identity matrix. Using the above property, the determinant of the matrix given below is …

In the circuit shown below, if the source voltage $V_S = 100\angle 53.13^{\circ}\: V$ then the Thevenin’s equivalent voltage in Volts as seen by the load resistance $R_{L}$ is

The open-loop transfer function of a dc motor is given as $\dfrac{\omega(s)}{V_{a}(s)} = \dfrac{10}{1+10s}.$ When connected in feedback as shown below, the approximate value of $K_{a}$ that will reduce the time constant of the closed loop system by one hundred times as compared to that of the open-loop system is

In the circuit shown below, the knee current of the ideal Zener diode is $10\: mA.$ To maintain $5\: V$ across $R_{L},$ the minimum value of $R_{L}$ in $\Omega$ and the minimum power rating of the Zener diode in $mW,$ respectively, are

The following arrangement consists of an ideal transformer and an attenuator which attenuates by a factor of $0.8.$ An ac voltage $V_{WX1} = 100V$ is applied across $WX$ to get an open circuit voltage $V_{YZ1}$ across $YZ.$ Next, an ac voltage $V_{YZ2}= 100V$ is applied across $YZ$ to get an open circuit voltage $V_{WX2}$ across $WX.$ Then …

Two magnetically uncoupled inductive coils have $Q$ factors $q_{1}$ and $q_{2}$ at the chosen operating frequency. Their respective resistances are $R_{1}$ and $R_{2}.$ When connected in series, their effective $Q$ factor at the same operating frequency is

The impulse response of a continuous time system is given by $h(t) = \delta(t-1) + \delta(t-3).$ The value of the step response at $t = 2$ is

The small-signal resistance $(i.e., dV_{B}/dI_{D})$ in $k\Omega$ offered by the $n$-channel $MOSFET\: M$ shown in the figure below, at a bias point of $V_{B} = 2\: V$ is (device data for $M:$ device transconductance parameter $k_{N} = \mu_{n} C'_{ox} (W/L) = 40\: \mu A/V^{2},$threshold voltage $V_{TN} = 1\: V,$ and neglect body effect and …

The ac schematic of an $NMOS$ common-source stage is shown in the figure below, where part of the biasing circuits has been omitted for simplicity. For the $n$-channel $MOSFET\: M,$ the transconductance $g_{m} = 1\; mA/V,$ and body effect and channel length modulation effect are to be neglected. The lower cutoff frequency in $Hz$ of the circuit is …

A system is described by the differential equation $\dfrac{\mathrm{d}^{2} y}{\mathrm{d} x} + 5\dfrac{\mathrm{d}y }{\mathrm{d} x} + 6y(t) = x(t).$ Let $x(t)$ be a rectangular pulse given by $x(t) = \begin{cases} 1&0<t<2 \\ 0&\text{otherwise} \end{cases}$ Assuming that $y(0) = 0$ and $\dfrac{\mathrm{d}y }{\mathrm{d} x} = 0$ at $t=0,$ …

A system described by a linear, constant coefficient, ordinary, first order differential equation has an exact solution given by $y(t)$ for $t>0,$ when the forcing function is $x(t)$ and the initial condition is $y(0).$ If one wishes to modify the system so that the solution becomes $-2y(t)$ for $t>0,$ we need to

Consider two identically distributed zero-mean random variables $U$ and $V.$ Let the cumulative distribution functions of $U$ and $2V$ be $F(x)$ and $G(x)$ respectively. Then, for all values of $x$

The $\text{DFT}$ of a vector $\begin{bmatrix} a & b & c & d \end{bmatrix}$ is the vector $\begin{bmatrix} \alpha & \beta & \gamma & \delta \end{bmatrix}.$ consider the product …

The signal flow graph for a system is given below. The transfer function $\dfrac{Y(s)}{U(s)}$ for this system is

In the circuit shown below the $\text{op-amps}$ are ideal. Then $V_{\text{out}}$ in $\text{Volts}$ is

In the circuit shown below, $Q_{1}$ has negligible collector-to-emitter saturation voltage and the diode drops negligible voltage across it under forward bias. If $V_{cc}$ is $+5 V, X$ and $Y$ are digital signals with $0\: V$ as logic $0$ and $V_{cc}$ as logic $1,$ then the Boolean expression for $Z$ is

A voltage $1000 \sin\omega t\:\: \text{Volts}$ is applied across $YZ.$ Assuming ideal diodes, the voltage measured across $WX$ in $\text{Volts},$ is

Three capacitors $C_{1}, C_{2}$ and $C_{3}$ whose values are $10\mu F, 5\mu F,$ and $2\mu F$ respectively, have breakdown voltages of $10V, 5V,$ and $2V$ respectively. For the interconnection shown below, the maximum safe voltage in Volts that can be applied across the combination, and the corresponding total charge in $\mu C$ stored in the …

There are four chips each of $1024\:\text{bytes}$ connected to a $16\:\text{bit}$ address bus as shown in the figure below. $RAMs\: 1, 2, 3$ and $4$ respectively are mapped to addresses