GATE EC question library

In the $\text{BJT}$ amplifier shown in the figure is the transistor is based in the forward active region. Putting a capacitor across $R_E$ will

The skin depth at $10\; \mathrm{MHz}$ for a conductor is $1 \; \mathrm{cm}$. The phase velocity of an electromagnetic wave in the conductor at $1,000 \; \mathrm{MHz}$ is about

A very lossy, $\lambda / 4$ long, $50 \; \Omega$ transmission line is open circuited at the load end. The input impedance measured at the other end of the line is approximately

A parabolic dish antenna has a conical beam $2^{\circ}$ wide, the directivity of the antenna is approximately

An amplifier A has $6 \; d \mathrm{B}$ gain and $50 \; \Omega$ input and output impedances. The noise figure of this amplifier as shown in the figure is $(a)$ is $3 \; d \mathrm{B}$. A cascade of two such amplifiers as in the figure is will have a noise figure of

The power spectral density of a deterministic signal is given by $\left[\sin (f) / f^{2}\right]$ where $f$ is frequency. The autocorrelation function of this signal in the time domain is

A communication channel has first-order low pass transfer function. The channel is used to transmit pulses at a symbol rate greater than the half-power frequency of the low pass function. Which of the network shown in the figure is can be used to equalise the received pulses?

A certain linear time invariant system has the state and the output equations given below …

In the signal flow graph of the figure is $\text{y/ x}$ equals

In the circuit of in the figure is the current $i_{D}$ through the ideal diode (zero cut in voltage and forward resistance) equals

In the circuit of the figure is the equivalent impedance seen across terminals $\text{a, b}$ is

In the circuit of the figure is the energy absorbed by the $4 \; \Omega$ resistor in the time interval $(0, \infty)$ is

The boolean function $\mathrm{A}+\mathrm{BC}$ is a reduced form of

The gate delay of an $\text{NMOS}$ inverter is dominated by charge time rather than discharge time because

In a $\text{J-K}$ flip-flip we have $\text{J=Q}$ and $\text{K}=1$. Assuming the flip flop was initially cleared and then clocked for $6$ puleses, the sequence at the $\text{Q}$ output will be

For the $\text{NMOS}$ logic gate shown in the figure is the logic function implemented is

The intrinsic carrier density at $300 \mathrm{~K}$ is $1.5 \times 10^{10}$ / $\mathrm{cm}^{3}$, in silicon. For $n$-type silicon doped to $2.25 \times$ $10^{15}$ atoms $/ \mathrm{cm}^{3}$, the equilibrium electron and hole densities are

A half wave rectifier uses a diode with a forward resistance $\text{Rf}$. The voltage is $\text{V}_\text{m} \sin \omega t$ and the load resistance is $\text{R}_\text{L}$. The $\text{DC}$ current is given by

A signed integer has been stored in a byte using the $2$'s complement format. We wish to store the same integer in a $16$ bit word. We should

The following insturctions have been executed by an $8085 \; \mu \mathrm{P}$ $\begin{array}{cl}\text{ ADDRESS (HEX) } & \text{ INSTRUCTION } \\ 6010 & \text{ LXI H, 8A } 79 \mathrm{H} \\ 6013 & \text{ MOV A, L } \\ 6015 & \text{ ADDH } \\ 6016 & \text{ DAA } \\ 6017 & \text{ MOV H, A } \\ 6018 & \text{ PCHL }\end{array}$ From …