2007|Electronics and Comm (GATE Exam)-Previous Question Paper Solution

An 8085 assembly language program is given below.
Line 1: MVI A, B5H
2: MVI B, 0EH
3: XRI 69H
4: ADD B
5: ANI 9BH
6: CPI 9FH
7: STA 3010H
8: HLT

The contents of the accumulator just after execution of the ADD instruction in line 4 will be

An 8085 assembly language program is given below.
Line 1: MVI A, B5H
2: MVI B, 0EH
3: XRI 69H
4: ADD B
5: ANI 9BH
6: CPI 9FH
7: STA 3010H
8: HLT

After execution of line 7 of the program, the status of the CY and Z flags will be

The circuit diagram of a standard TTL NOT gate is shown in the figure. When V_i = 2.5 V, the modes of operation of the transistors will be

Two 5-bit binary numbers, i.e. X = 01110 and Y = 11001 are represented in two’s complement format. The sum of X and Y represented in two’s complement format using 6 bits is

The following binary values were applied to the X and Y inputs of the NAND latch shown in the figure in the sequence indicated below:
X = 0, Y = 1; X = 0, Y = 0; X = 1, Y = 1.
The corresponding stable P, Q outputs will be

A load of 50$\Omega$is connected in shunt in a 2-wire transmission line of Z₀ = 50 $\Omega$as shown in the figure. The 2-port scattering parameter matrix (S-matrix) of the shunt element is

The parallel branches of a 2-wire transmission line are terminated in 100 $\Omega$ and 200 $\Omega$ resistors as shown in the figure. The characteristic impedance of the line is Z₀ = 50 $\Omega$ and each section has a length of $\dfrac{\lambda}{4}$. The voltage reflection coefficient at the input is

A plane wave of wavelength ^$\lambda$ is travelling in a direction making an angle 30° with positive x-axis and 90° with positive y-axis. The ^{$\vec E$} field of the plane wave can be represented as (E₀ is constant)

A $\dfrac{\lambda}{2}$ dipole is kept horizontally at a height of $\dfrac{\lambda_0}{2}$ above a perfectly conducting infinite ground plane. The radiation pattern in the plane of the dipole ($\vec E$ plane) looks approximately as

A right circularly polarised (RCP) plane wave is incident at an angle of 60° to the normal, on an air-dielectric interface. If the reflected wave is linearly polarised, the relative dielectric constant ^{$\epsilon_{r2}$} is

The DC current gain ($\beta$)of a BJT is 50. Assuming that the emitter injection efficiency is 0.995, the base transport factor is

The electron and hole concentrations in an intrinsic semiconductor are n_i per cm³ at 300 K. Now, if acceptor impurities are introduced with a concentration of N_A per cm³ where (where N_A >> n_i), the electron concentration per cm³ at 300 K will be

A p ⁺n junction has a built-in potential of 0.8 V. The depletion layer width at a reverse bias of 1.2V is 2 $\mu$m. For a reverse bias of 7.2 V, the depletion layer width will be

The raised cosine pulse p(t) is used for zero ISI in digital communications. The expression for p(t) with unity roll - off factor is given by p(t) =$\dfrac{sin \ 4\pi Wt}{4\pi Wt(1 - 16 w^2t^2)}$
The value of p(t) at t = $\dfrac{1}{4W}$is

In a GSM system, 8 channels can co-exist in 200 KHz bandwidth using TDMA. A GSM based cellular operator is allocated 5 MHz bandwidth. Assuming a frequency reuse factor of ^{$\dfrac{1}{5}$} i.e a five-cell repeat pattern, the maximum number of simultaneous channels that can exist in one cell is

If R(^_$\tau$) is the autocorrelation function of a real, wide-sense stationary random process, then which of the following is NOT true?

If S(f) is the power spectral density of a real, wide-sense, stationary random process, then which of the following relations is true?

During transmission over a certain binary communication channel, bit errors occur independently with probability p. The probability of AT MOST one bit in error in a block of n bits is given by

In a Direct Sequence CDMA System, the chip rate is 1.2288 ^$\times$ 10⁶ chips per second. If the processing gain is desired to be at least 100, then the data rate

An input to a 6-level quantizer has the probability density function f(x) as shown in the figure. Decision boundaries of the quantizer are chosen so as to maximize the entropy of the quantizer output. It is given that 3 consecutive decision boundaries are -1, 0 and 1.

The values of a and b are

The z-transform X [z] of a sequence x[n] is given by x[z] =$\dfrac{0.5}{1-2z^{-1}}$. It is given that the region of convergence of X[z] includes the unit circle. The value of x[0] is

A 5-point sequence x (n) is given as X [–3] = 1, x [–2] = 1, x [–1] = 0, x [0] = 5, x [1] = 1. If x(^{$e^{j\omega}$}) denotes the discrete – time fourier transform of x [n], what is the value of ^{$\displaystyle \int_{-\pi}^\pi x(e^{j\omega})$$d\omega$}?

The frequency response of a linear, time-invariant system is given by H(f) = $\dfrac{5}{1 + j10\pi f}$
The step response of the system is

An independent voltage source in series with an impedance Z_S = R_S + jX_S delivers a maximum average power to a load impedance Z_L when

Two series resonant filters are as shown in the figure. Let the 3-dB bandwidth of Filter 1 be B₁ and that of Filter 2 be B₂. The value of $\dfrac{B_1}{B_2}$ is

The following plot shows a function y which varies linearly with x. The value of the integral I = ^{$\int\limits_1^2 y \hspace{0.2cm}dx$}is

It is given that X₁, X₂, …..X_M are M non-zero orthogonal vectors. The dimension of the vector space spanned by the 2M vectors X₁, X₂, …X_{M ,} - X_M is

An examination consists of two papers, Paper 1 and Paper 2. The probability of failing in Paper 1 is 0.3 and that in Paper 2 is 0.2. Given that a student has failed in Paper 2, the probability of failing in Paper 1 is 0.6. The probability of a student failing in both the papers is

The equation x³ -x² + 4x - 4 = 0 is to be solved using the Newton-Raphson method. If x = 2 is taken as the initial approximation of the solution, the next approximation using this method will be

Three functions f₁ (t), f₂ (t) and f₃ (t) which are zero outside the interval [0, T] are shown in the figure. Which of the following statements is correct?

_{If C is a closed curve enclosing a surface S, the magnetic field intensity} ^{$\overrightarrow{H}$}_{, the current density} ^{$\overrightarrow{j}$}_{and the electric flux density} ^{$\overrightarrow{D}$} _{are related by}

The solution of the differential equation K^{2 $\frac{d^2y}{dx^2}$} = y – y₂ under the boundary conditions
(i) y = y₁ at x = 0 and
(ii) y = y₂ at x = _^$\infty$, where k, y₁ and y₂ are constants, is

If a semi-circular contour D of radius 2 is as shown in the figure given below, the value of the integral ^{$\int_D N \frac{1}{(S^2 -1)}ds$} is

For the BJT circuit shown, assume that the $\beta$ of the transistor is very large and V_BE = 0.7 V. The mode of operation of the BJT is

For the Zener diode shown in the figure, the Zener voltage at the knee is 7 V. The knee current is negligible and the Zener dynamic resistance is 10 ^$\Omega$. If the input voltage (V_i) ranges from 10 V to 16 V, what will be the range of out put voltage (V₀)?

In the Op-Amp circuit shown, assume that the diode current follows the equation I = I_s exp (V/V_T). For V_i = 2V, V₀ = V₀₁, and for V_i = 4 V, V₀ = V₀₂. The relationship between V₀₁ and V₀₂ is

Group I lists four different semiconductor devices. Match each device in Group I with its characteristic property in Group II

In the CMOS inverter circuit shown, if the transconductance parameters of the NMOS and PMOS transistor are k_n = k_p = $\mu$_nC_0x $\frac{W_n}{L_n}$=$\mu$_p C_ox $\frac{W_p}{L_p}$= 40 $\mu$A/ V² and their threshold voltage are V_THn = |V_THp| = 1V, the current I is

The open loop transfer function of a plant is given as G(s) = ^{$\dfrac{1}{s^2-1}$}. If the plant is operated in a unity feedback configuration, the lead compensator that an stabilize this control system is

The asymptotic Bode plot of a transfer function is as shown in the figure. The transfer function G(s) corresponding to this Bode plot is

A control system with a PD controller is shown in the figure. If the velocity error constant K_V = 1000 and the damping ratio $\xi$= 0.5, the values of K_P and K_D are

A transmission line of characteristic impedance 50 Ω is terminated by a 50 Ωload.
When excited by a sinusoidal voltage source at 10 GHz, the phase difference between two points spaced 2 mm apart on the line is found to be $\frac{2 \pi}{\lambda}$ radians. The phase velocity of the wave along the line is

An air-filled rectangular waveguide has inner dimensions of 3 cm ^X 2 cm. The wave impedance of the TE₂₀ mode of propagation in the waveguide at a frequency of 30 GHz is (free space impedance _{^$\eta_0$}= 377^$\Omega$)

The transfer function of a plant is T (s) = $
\dfrac{5}{(s+5)(s^2+s+1)}
$. The second - order approximation of T(s) using dominate pole concept is

Consider the Op-Amp circuit shown in the figure.

If V_i = V₁ sin ($\omega t$) and V₀ = V₂ sin ($\omega t$+ $\phi$), the minimum and maximum values of $\phi$(in radians) are respectively