A 4 bit ripple counter and a 4 bit synchronous counter are made using flip-flops having a propagation delay of 10 ns each. If the worst case delay in the ripple counter and the synchronous counter be R and S respectively, then

The output of the 74 series of TTL gates is taken from a BJT in

The circuit shown in figure has 4 boxes each described by inputs P, Q, R and outputs Y, Z with Y = P $\oplus$Q $\oplus$R Z = RQ + $\bar P R + Q\bar P$

The circuit acts as a

The minimum number of comparators required to build an 8 it flash ADC is

The circuit shown in figure converts

The number of distinct Boolean expression of 4 variables is

The circuit shown in figure is a 4-bit DAC The input bits 0 and 1 are represented by 0 and 5 V respectively. The OP AMP is ideal, but all the resistances and the 5V inputs have a tolerance of $\pm$10%. The specification (rounded to the nearest multiple of 5%) for the tolerance of the DAC is

Without any additional circuitry, an 8 : 1 MUX can be used to obtain

In the circuit shown in Figure, A is a parallel in, parallel-out 4-bit register, which loads at the rising edge of the clock C. The input lines are connected to a 4-bit bus, W. Its output acts as the input to a 16$\times$4 ROM whose output is floating when the enable input E is 0. A partial table of the contents of the ROM is as follows:

$$ \begin{array}{c|c} \ Address & 0 & 2 & 4 & 6 & 8 & 10 & 11 & 14 \\ Data & 0011 & 1111 & 0100 & 1010 & 1011 & 1000 & 0010 & 1000 \end{array} $$

The clock to the register is shown, and the data on the W bus at time t₁ is 0110. The data on the bus at time t₂ is

If the functions W, X, Y and Z are as follows: W = R + ^{$\bar P Q + \bar RS$} X = PQ^{$\bar R \bar S + \bar P \bar Q \bar R \bar S + P \bar Q \bar R \bar S$} Y = RS + ^{$\overline{PR + P \bar Q + \bar P \bar Q}$} Z = R + S + ^{$\overline{PQ + \bar P \bar Q \bar R + P \bar Q \bar S}$} then

A 0 to 6 counter consists of 3 flip flops and a combination circuit of 2 input gate(s). The combination circuit consists of

The DTL, TTL, ECL and CMOS families of digital ICs are compared in the following 4 columns:

(P) (Q) (R) (S) Fanout is minimum DTL DTL TTL CMOS Power consumption is minimum TTL CMOS ECL DTL Propagation delay is minimum CMOS ECL TTL TTL
The correct column is

In an 8085 microprocessor, the instruction CMP B has been executed while the content of the accumulator is less than that of register B. As a result,

The unit of $\nabla$$\times$ H is

Medium 1 has the electrical permittivity $\xi_1$= 1.5 $\xi_0$ farad/m and occupies the region to the left of x = 0 plane. Medium 2 has the electrical permittivity $\xi_2$ = 2.5 $\xi_0$ farad/m and occupies the region to the right of x = 0 plane. If E₁ in medium 1 is E₁ = (2u_x -3u_y + 1u_z) volt/m, then E₂ in medium 2 is

The bandgap of silicon at 300 K is

A particular green LED emits light of wavelength 5490°A. The energy bandgap of the semiconductor material used there is (Planck's constant = 6.626$\times$10^-34J -s)

If the electric field intensity is given by E = (xu_x + yu_y + zu_z) volt/m, the potential difference between X(20,0) and Y(1,2,3) is

A uniform plane wave travelling in air is incident on the plane boundary between air and another dielectric medium with $\epsilon_r$= 4. The reflection coefficient for the normal incidence, is

The depth of penetration of electromagnetic wave in a medium having conductivity $\sigma$ at a frequency of 1 MHz is 25 cm. The depth of penetration at a frequency of 4 MHz will be

A rectangular metal wave-guide filled with a dielectric material of relative permittivity $\epsilon_r$ = 4 has the inside dimensions 3.0 cm $\times$ 1.2 cm. The cut-off frequency for the dominant mode is

Two identical antennas are placed in the $\theta$= $\dfrac{\pi}{2}$ plane as shown in figure. The elements have equal amplitude excitation with 180° polarity difference, operating at wavelength $\lambda$. The correct value of the magnitude of the far-zone resultant electric field strength normalized with that of a single element, both computed for $\phi$= 0, is

The electron concentration in a sample of uniformly doped n-type silicon at 300 K varies linearly from 10¹⁷/cm³ at x = 0 to 6 $\times$10¹⁶/cm³ at x = 2 $\mu$m. Assume a situation that electrons are supplied to keep this concentration gradient constant with time. If electronic charge is 1.6$\times$10^-19 coulomb and the diffusion constant Dn = 35 cm²/s, the current density in the silicon, if no electric field is present, is

If P is Passivation, Q is n-well implant, R is metallization and S is soruce/drain diffusion, then the order in which they are carried out in a standard n-well CMOS fabrication process, is

At 300 K, for a diode current of 1 mA, a certain germanium diode requires a forward bias of 0.1435V, whereas a certain silicon diode requires a forward bias of 0.718 V. Under the conditions stated above, the closest approximation of the ratio of reverse saturation current in germanium diode to that in silicon diode is

n-type silicon is obtained by doping silicon with

For an n-channel enhancement type MOSFET, if the source is connected at a higher potential than that of the bulk, (i.e. V_SB > 0) the threshold voltage V_T of the MOSFET

When the gate-to-source voltage (VGS) of a MOSFET with threshold voltage of 400 mV, working in saturation is 900 mV, the drain current in observed to be 1 mA. Neglecting the channel width modulation effect and assuming that the MOSFET is operating at saturation, the drain current for an applied VGS of 1400 mV is

The action of a JFET in its equivalent circuit can best be represented as a

The input to a coherent detector is DSB-SC signal plus noise. The noise at the detector output is

Let x(t) = 2 cos (800$\pi$t) + cos (1400$\pi$t). x(t) is sampled with the rectangular pulse train shown in figure. The only spectral components (in kHz) present in the sampled signal in the frequency range 2.5 kHz to 3.5 kHz are

Choose the correct one from among the alternatives A, B, C, D after matching an item in Group 1 with the most appropriate item in Group 2.||| |---|---| | Group 1| Group 2| | P Ring modulator| 1 Clock recovery| | Q VCO| 2 Demodulation of FM| | R Foster-Seely discriminator| 3 Frequency conversion| | S Mixer| 4 Summing the two inputs| | | 5 Generation of FM| | | 6 Generation of DSB-Sc|

Let X and Y be two statistically independent random variables uniformly distributed in the ranges (-1,1) and (-2,1) respectively. Let Z = X + Y, then the probability that [Z$\le$-2] is

Let Y and Z be the random variables obtained by sampling X(t) at t = 2 and t = 4 respectively. Let W = Y - Z. The variance of W is

The noise at the input to an ideal frequency detector is white. The detector is operating above threshold. The power spectral density of the noise at the output is

X(t) is a random process with a constant mean value of 2 and the autocorrelation function R_x ($\tau$) = 4$\lfloor e^{-0.2 | d} + 1 \rfloor$.

Let X be the Gaussian random variable obtained by sampling the process at t = ti and let Q ($\alpha$) = $\int_\infty^\infty \dfrac{1}{\sqrt {2\pi}} e^{\dfrac{-y^2}{2}} dy$ The probability that [ x $\le$ 1 ] is

c(t) and m(t) are used to generate an FM signal. If the peak frequency deviation of the generated FM signal is three times the transmission bandwidth of the AM signal, then the coefficient of the term cos[2$\pi$(1008 $\times$10³t)] in the FM signal (in terms of the Bessel coefficients) is

Let m (t) = cos [ (4^{_$\pi$ $\times$} 10³) t] be the message signal and c(t) = 5 cos[(2^{_$\pi$ $\times$} 10⁶)t] be the carrier. c(t) and m(t) are used to generate an AM signal. The modulation index of the generated AM signal is 0.5. Then the quantity ^{$\dfrac{Total sideband power}{Carrier power}$} is

At a given probability of error, the binary coherent FSK is inferior to binary coherent PSK by

A DSB-SC signal is to be generated with a carrier frequency fc = 1 MHz using a nonlinear device with the input-output characteristic V₀ = a₀v_i + a₁v_i³ where a0 and a1 are constants. The output of the nonlinear device can be filtered by an appropriate band-pass filter. Let v_i = A'_c cos (2$\pi$f'_c t) + m(t) where m(t) is the message signal. The value of f'_c (in MHz) is

A sinusoidal signal with peak-to-peak amplitude of 1.536 V is quantised into 128 levels using a mid-rise uniform quantiser. The quantisation noise power is

If E_b, the energy per bit of a binary digital signal, is 10^-6 watt-sec and the onesided power spectral density of the white noise, N₀ = 10^-5 W/Hz, then the output SNR of the matched filter is

The input to a linear delta modulator having a step-size ^$\Delta$ = 0.628 is a sine wave with frequency f_m and peak amplitude E_m. If the sampling frequency f_s = 40 kHz, the combination of the sine wave frequency and the peak amplitude, where slope overload will take place, is

A super heterodyne receiver is to operate in the frequency range 550 kHz - 1650 kHz, with the intermediate frequency of 450 kHz. Let R = $\dfrac{C_{max}}{C_{min}}$ denote the required capacitance ratio of the local oscillator and I denote the image frequency (in kHz) of the incoming signal. If the receiver is tuned to 700 kHz, then

If S represents the carrier synchronization at the receiver and ^_$\rho$ represents the bandwidth efficiency, then the correct statement for the coherent binary PSK is

A signal is sampled at 8 kHz and is quantized using 8-bit uniform quantizer. Assuming SNRq for a sinusoidal signal, the correct statement for PCM signal with a bit rate of R is

The Fourier series expansion of a real periodic signal with fundamental frequency f₀ is given by g_p (t) = $\displaystyle \sum_{n=-\infty}^\omega C_n e^{j^2 x n f_0 t}$it is given that C3 = 3 + j5. Then C-3 is

The Laplace transform of i(t) is given by I(s) = $\dfrac{2}{s(1+s)}$ As t $\rightarrow$$\infty$, the value of i(t) tends to

A sequence x(n) with the z-transform X(z) = z⁴ + z² -2z + 2-3z^-4 is applied as an input to a linear, time-invariant system with the impulse response h(n) = 2$\delta$(n-3) where $\delta$(n) = $ \begin{cases} 1, n = 0 \\ 0, otherwise \end{cases}

$ The output at n = 4 is

The system under consideration is an RC low-pass filter (RC-LPF) with R = 1.0 k$\Omega$and C = 1.0 $\delta$F.

Let tg(f) be the group delay function of the given RC-LPF and f2 = 100 Hz. Then tg(f2) in ms, is

The system under consideration is an RC low-pass filter (RC-LPF) with R = 1.0 k$\Omega$and C = 1.0$\mu$F.

Let H(f) denote the frequency response of the RC-LPF. Let f1 be the highest frequency such that 0$\le$|f| $\le$f₁, $\dfrac{ | H(f_1) | }{H(0)}$$\ge$ 0.95. Then f₁ (in Hz) is

Let x(t) be the input to a linear, time-invariant system. The required output is 4x (t-2). The transfer function of the system should be

Let P be linearity, Q be time-invariance, R be causality and S be stability. A discrete time system has the input-output relationship, Y(n) = $ \begin{cases} x(n), & n \ge 1 \\ 0 & n=0 \\ x(n+1), & n \le -1 \end{cases}

$ where x(n) is the input and y(n) is the output. The above system has the properties

A series RLC circuit has a resonance frequency of 1 kHz and a quality factor Q = 100. If each R, L and C is doubled from its original value, the new Q of the circuit is

The driving point impedance Z(s) of a network has the pole-zero locations as shown in the figure below. If Z(0) = 3, then Z(s) is

The minimum number of equations required to analyse the circuit shown in the figure below is

The current flowing through the resistance R in the circuit in figure has the form P cos 4t, where P is

A source of angular frequency 1 rad/sec has a source impedance consisting of 1 $\Omega$resistance in series with 1 H inductance. The load that will obtain the maximum power transfer is

Assume that the switch S is in position 1 for a long time and thrown to position 2 at t = 0.

At t = 0⁺, the current i₁ is

The differential equation for the current i(t) in the circuit of figure given below is

Assume that the switch S is in position 1 for a long time and thrown to position 2 at t = 0.

I₁ (s) and I₂ (s) are the Laplace transforms of i₁ (t) and i₂ (t) respectively. The equation for the loop current I₁ (s) and I₂ (s) for the circuit shown in figure Q.33-34, after the switch is brought from position 1 to position 2 at t = 0, are

The impedance parameters Z11 and Z12 of the two-port network in figure are

Twelve 1$\Omega$ resistances are used as edges to form a cube. The resistance between two diagonally opposite corners of the cube is

An input voltage v(t) = 10^{$\sqrt 2$} cos(t+10⁰) + 10^{$\sqrt 3$} cos (2t+10^o)V is applied to a series combination of resistance R = 1 _^$\Omega$ and an inductance L = 1 H. The resulting steady state current i(t) in ampere is

The circuit shown in figure is best described as a

Choose proper substitutes for X and Y to make the following statement correct. Tunnel diode and Avalanche photodiode are operated in X bias and Y bias respectively.

If the differential voltage gain and the common mode voltage gain of a differential amplifier are 48 dB and 2 dB respectively, then its common mode rejection ratio is

Generally, the gain of a transistor amplifier falls at high frequencies due to the

If the input to the ideal comparator shown in figure is a sinusoidal signal of 8V (peak to peak) without any DC component, then the output of the comparator has a duty cycle of

Choose the correct match for input resistance of various amplifier configurations shown below ||| |---|---| | Configuration| Input resistance| | CB: Common Base| O: Low| | CC: Common Collector| MO: Moderate| | CE: Common Emitter| HI: High|

A PD controller is used to compensate a system. Compared to the uncompensated system, the compensated system has

The figure shows the Nyquist plot of the open-loop transfer function G(s)H(s) of a system. If G(s)H(s) has one right hand pole, the closed loop system is

An n-type silicon bar 0.1 cm long and $\mu$m² in cross-sectional area has a majority carrier concentration of 5 $\times$ 10²⁰/m³ and the carrier mobility is 0.13 m²/V-s at 300K. If the charge of an electron is 1.6$\times$10^-19 coulomb, then the resistance of the bar is

The intrinsic carrier concentration of silicon sample of 300 K is 1.5 $\times$ 10¹⁶/m³. If after doping, the number of majority carriers is 5 $\times$ 10²⁰/m³, the minority carrier density is

The output voltage of the regulated power supply shown in figure is

What is the frequency of radio waves radiated out by an oscillating circuit consisting of condenser of capacity 0.02 microfarad and inductance 8 microhenry?

Match items in Group 1 with items in Group 2, most suitably ||| |---|---| | Group 1| Group 2| | P LED| 1 Heavy doping| | Q Avalanche photodiode| 2 Coherent radiation| | R Tunnel diode| 3 Spontaneous emission| | S LASER| 4 Current gain|

If the op-amp in figure is ideal, the output voltage V_out will be equal to

In the amplifier circuit shown in figure, the values of R₁ and R₂ are such that the transistor is operating at V_CE = 3V and I_C = 1.5mA when its $\beta$is 150. For a transistor with $\beta$of 200, the operating point (V_CE, I_C) is

An amplifier without feedback has a voltage gain of 50, input resistance of 1 K$\Omega$ and output resistance of 2.5 K$\Omega$. The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2, is

Three identical amplifiers with each one having a voltage gain of 50, input resistance of 1 K$\Omega$and output resistance of 250 $\Omega$, are cascaded. The open circuit voltage gain of the combined amplifier is

An ideal sawtooth voltage waveform of frequency 500 Hz and amplitude 3 V is generated by charging a capacitor of 2 $\mu$F in every cycle. The charging requires

The signal flow graph of a system is shown in figure. The transfer function $\dfrac{C(s)}{R(s)}$ of the system is

The root locus of the system G (s) H(s) = $\dfrac{k}{s(s+2)(s+3)}$ has the break - away point located at

The gain margin and the phase margin of a feedback system with G (s) H(s) = $\dfrac{s}{(s+100)^3}$are

The approximate Bode magnitude plot of a minimum-phase system is shown in figure. The transfer function of the system is

A second-order system has the transfer function ^{$\dfrac{C(s)}{R(s)}$} = ^{$\dfrac{4}{s^2+4s+4}$} with r(t) as the unit-step function, the response c(t) of the system is represented by

The zero-input response of a system given by the state-space equation is

A short-circuited stub is shunt connected to a transmission line as shown in figure. If Z₀ = 50 ohm, the admittance Y seen at the junction of the stub and the transmission line is

If the electric field intensity associated with a uniform plane electromagnetic wave traveling in a perfect dielectric medium is given by E(z,t) = 10 cos (2^{_{$\pi$$\times$}} 10⁷t = 0.1^_$\pi$z) volt/m, then the velocity of the traveling wave is