GATE EC question library

A medium wave radio transmitter operating at a wavelength of $492 \mathrm{~m}$ has a tower antenna of height $124 \mathrm{~m}$. What is the radiation resistance of the antenna?

A uniform plane electromagnetic wave incident normally on a plane surface of a dielectric material is reflected with a VSWR of $3.$ What is the percentage of incident power that is reflected?

A material has conductivity of $10^{-2} \mathrm{mho/m}$ and a relative permittivity of $4.$ The frequency at which the conduction current in the medium is equal to the displacement current is

The PSD and the power of a signal $g(t)$ are, respectively, $\mathrm{S}_{\text{g}}(\omega)$ and $\text{P}_{\text{g}}$. The PSD and the power of the signal $a \text{g}(t)$ are, respectively,

During transmission over a communication channel, bit errors occur independently with probability p. If a block of $n$ bits is transmitted, the probability of at most one bit error is equal to

The Nyquist sampling interval, for the signal $\text{Sin c } (700 t)+\text{Sin c } (500 t)$ is

A video transmission system transmits $625$ picture frames per second. Each frame consists of a $400 \times 400$ pixel grid with $64$ intensity levels per pixel. The data rate of the system is

The feeback control system in the figure is stable.

The open-loop $\text{DC}$ gain of a unity negative feedback system with closed-loop transfer function $\frac{s+4}{s^{2}+7 s+13}$ is

An electrical system and its signal-flow graph representations are shown in the figure respectively. The values of $G_{2}$ and $H$, respectively, are

The impulse response functions of four linear systems $\mathrm{S}_{1}, \mathrm{~S}_{2}, \mathrm{~S}_{3}, \mathrm{~S}_{4}$ are given respectively by $\begin{array}{ll} h_{1}(t)=1 & h_{2}(t)=U(t) \\ h_{3}(t)=\frac{U(t)}{t+1} & h_{4}(t)=e^{3 t} U(t) \end{array}$ Where $\mathrm{U}(t)$ is the unit step function. Which of these systems is time …

In the TTL circuit in the figure, $\mathrm{S}_{2}$ to $\mathrm{S}_{0}$ are select lines and $\text{X}_{7}$ to $\text{X}_{0}$ are input lines. $\text{S}_{0}$ and $\text{X}_{0}$ are LSBs. The output $Y$ is

In the figure, the $\text{LED}$

In the figure, assume the OP-AMPs to be ideal. The output $v_{0}$ of the circuit is

The inverting OP-AMP shown in the figure has an open-loop gain of $100.$ The closed-loop gain $\frac{v_{0}}{v_{s}}$ is

The oscillator circuit shown in the figure,

The transistor shunt regulator shown in the figure is has a regulated output voltage of $10 \mathrm{~V}$, when the input varies from $20 \mathrm{~V}$ to $30 \mathrm{~V}$. The relevant parameters for the zener diode and the transistor are: $\mathrm{V}_{\text{Z}}=9.5, \mathrm{~V}_{\text{SE }}=0.3 \mathrm{~V}, \beta=99$. Neglect the current through …

An npn $\text{BJT}$ has $\mathrm{gm}=38 \mathrm{~m} \mathrm{~A} / \mathrm{V}, \mathrm{C}_{u}=10^{-14} \mathrm{~F}$, $C_{\pi}=4 \times 10^{-13} \mathrm{~F}$, and $D C$ current gain $\beta_{0}=90$. For this transistor $f_{\mathrm{T}}$ and $f_{\beta}$ are

The $Z$ parameters $Z_{11}$ and $Z_{21}$ for the $2$-port network in the figure,

In the figure, the value of the load resistor $R$ which maximizes the power delivered to it is