MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 905 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 801. |
Which of the following circuits come under the class of sequential logic circuits? Full adderFull subtractor Half adderJ-K flip-flopCounter Select the correct answer from the codes given below: |
| A. | 1 and 2 |
| B. | 1, 2 and 3 |
| C. | 3 and 4 |
| D. | 4 and 5 |
| Answer» E. | |
| 802. |
When x(n) is real then the Fourier series coefficients are correlated as __________ . |
| A. | a-k = ak* |
| B. | ak = ak* |
| C. | ak+1 = ak* |
| D. | a-k+1 = ak* |
| Answer» B. ak = ak* | |
| 803. |
The order of the differential equation is |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 804. |
Hysteresis loss in a transformer working at 220 V and at a frequency of 50 Hz is 100 W. When the transformer is operated at 220 V and at a frequency of 100 Hz, what is the hysteresis loss? |
| A. | 50 W |
| B. | 100 W |
| C. | 200 W |
| D. | 400 W |
| Answer» B. 100 W | |
| 805. |
The spectral range of a band pass signal extends from 10 MHz to 10.4 MHz. What is the minimum sampling frequency required for reconstruction? |
| A. | 20 MHz |
| B. | 20.8 MHz |
| C. | 20.4 MHz |
| D. | 0.8 MHz |
| Answer» E. | |
| 806. |
In the following network, the switch is closed at t = 0- and the sampling starts from t = 0. The sampling frequency is 10Hz.The expression and the region of convergence of the z-transform of the sampled signal are |
| A. | |z| < e-5 |
| B. | |z| < e-0.05 |
| C. | |z| < e-0.05 |
| D. | |z| > e-5 |
| Answer» D. |z| > e-5 | |
| 807. |
What was the first commercial geostationary communication satellite? |
| A. | INTELSAT 1 |
| B. | ECHO |
| C. | INSAT-1A |
| D. | SPUTNIK |
| Answer» B. ECHO | |
| 808. |
If the sequence converges, then the series converges absolutely is |
| A. | Ratio test |
| B. | Root test |
| C. | Divergence test |
| D. | Convergence test |
| Answer» C. Divergence test | |
| 809. |
An electromechanical closed loop control system has the following characteristics equation :s3 + 6Ks2 + (K + 2)s = 8where K is the forward gain of the system. The condition for closed loop stability is |
| A. | K = 0.528 |
| B. | K = 2 |
| C. | K = 0 |
| D. | K = -2528 |
| Answer» B. K = 2 | |
| 810. |
Denominator polynomial of a transfer function of certain network is: s3 + s2 + 2s + 24 Then the network is: |
| A. | stable |
| B. | oscillatory |
| C. | unstable |
| D. | depends on numerator polynomial |
| Answer» D. depends on numerator polynomial | |
| 811. |
A scheme shown below is to generate a wide band FM modulate signal. Narrow band FM has carrier frequency = 400 KHz Deviation ratio = 0.2 Wide band FM has carrier frequency = 100 MHz Deviation ratio = 6 Local oscillator frequencies can be |
| A. | 88 MHz, 112 MHz |
| B. | 96 MHz, 104 MHz |
| C. | 92 MHz, 108 MHz |
| D. | 90 MHz, 110 MHz |
| Answer» B. 96 MHz, 104 MHz | |
| 812. |
Find the value of K and velocity constant Kv so that the maximum overshoot in the unit step response is 0.2 and the peak time is 1 sec. |
| A. | 12.37, 0.175 |
| B. | 12.86, 2.175 |
| C. | 11.36, 1.175 |
| D. | 1.86, 0.175 |
| Answer» B. 12.86, 2.175 | |
| 813. |
Consider a stable and causal system with impulse response h(t) and system function H(S). Suppose H(S) is rational, contains a pole at S = - 2, and does not have a zero at the origin. The location of all other poles and zero is unknown for each of the following statements. Let us determine whether statement is true or false. f[h(t) e-3t] convergesh(t) has finite durationH(s) = H(- s) Choose correct option. |
| A. | 1 - True, 2 - False, 3 - True, 4 - False |
| B. | 1 - False, 2 - False, 3 - False, 4 - True |
| C. | 1 - False, 2 - False, 3 - False, 4 - False |
| D. | 1 - True, 2 - can't say, 3 - True, 4 - can't say |
| Answer» D. 1 - True, 2 - can't say, 3 - True, 4 - can't say | |
| 814. |
Consider the following statements:To draw a.c. equivalent circuit of a transistors, all d.c. sources are shorteda.c. sources are shortedd.c. sources are openeda.c. sources are connected to d.c. sources Which of the above statements is/are correct? |
| A. | 2 and 4 |
| B. | 1 and 2 |
| C. | 1 only |
| D. | 3 and 4 |
| Answer» D. 3 and 4 | |
| 815. |
(11)2 + (11)3 = (11)? |
| A. | 4 |
| B. | 5 |
| C. | 6 |
| D. | none |
| Answer» D. none | |
| 816. |
What will be equipotential surfaces for a pair of equal and opposite line charges? |
| A. | Spheres |
| B. | Concentric cylinders |
| C. | Non-concentric cylinders |
| D. | None of the above |
| Answer» D. None of the above | |
| 817. |
Consider the voltage transfer characteristic of a standard CMOS inverterwhere region A corresponds to |
| A. | NMOS and PMOS triode |
| B. | Both are saturation |
| C. | NMOS saturated PMOS linear |
| D. | None of these |
| Answer» D. None of these | |
| 818. |
The open loop transfer function of a unity feedback system is: The range of K for which the system is stable is |
| A. | |
| B. | 13 > K > 0 |
| Answer» B. 13 > K > 0 | |
| 819. |
The polar plot for positive frequencies is shown below. The gain margin is |
| A. | - 8.02 dB |
| B. | 6.02 dB |
| C. | 5 dB |
| D. | none of these |
| Answer» E. | |
| 820. |
If g(t) = e- p t2 then G(0) is __________ (where g(t)‚áî G(f) |
| A. | |
| B. | unity |
| Answer» C. | |
| 821. |
Consider the following statements: Acceptor level is formed very close to the conduction band.The effective mass of the free electron is same as that of a hole.The magnitude of the charge of a free electron is same as that of a hole.Addition of donor impurities adds holes to the semiconductor. Which of the above statements are correct? |
| A. | 1 and 3 |
| B. | 2 and 3 |
| C. | 2 and 4 |
| D. | 3 and 4 |
| Answer» C. 2 and 4 | |
| 822. |
A system with transfer function has an output for the input signal . Then, the system parameter 'p' is |
| A. | 3 |
| B. | |
| Answer» C. | |
| 823. |
A TV picture is to be transmitted over a channel of 6 MHz bandwidth at a 35 dB S/N ratio. The capacity of the channel is |
| A. | 50 Mbps |
| B. | 100 Mbps |
| C. | 36 Mbps |
| D. | 72 Mbps |
| Answer» E. | |
| 824. |
Consider an AM system using a square law detector as shown in figure.XC(t) = AC[1 + u x (t)] cos ωct, |ux(t)| |
| A. | A2Cu2 E[x2(t)] |
| B. | A2Cu2 E(x) |
| C. | |
| Answer» B. A2Cu2 E(x) | |
| 825. |
A uniform plane magnetic wave incident normally on a plane surface of a dielectric material is reflected and the percentage of reflected power is 75% What is VSWR? |
| A. | 14 |
| B. | 1.4 |
| C. | 15 |
| D. | 13 |
| Answer» B. 1.4 | |
| 826. |
The current I for the network |
| A. | 0 mA |
| B. | 10.72 mA |
| C. | 10.94 mA |
| D. | 11.32 mA |
| Answer» C. 10.94 mA | |
| 827. |
The amplifier circuit shown below uses a silicon transistor. The capacitors Cc and CE can be assumed to be short at signal frequency and the effect of output resistance r0 can be ignored. If CE is disconnected from the circuit, which one of the following statements is TRUE? |
| A. | The input resistance Ri increases and the magnitude of voltage gain Av decreases |
| B. | The input resistance Ri decreases and the magnitude of voltage gain Av decreases |
| C. | Both input resistance Ri and the magnitude of voltage gain Av decrease |
| D. | Both input resistance Ri and the magnitude of voltage gain Av increase |
| Answer» B. The input resistance Ri decreases and the magnitude of voltage gain Av decreases | |
| 828. |
The type of feedback in the following circuit diagram |
| A. | Voltage shunt |
| B. | Current-shunt |
| C. | Voltage series |
| D. | Current series |
| Answer» D. Current series | |
| 829. |
Consider a system with the transfer function . Its damping ratio will be 0.5 when the value of k is : |
| A. | 43618 |
| B. | 3 |
| C. | 43617 |
| D. | 6 |
| Answer» D. 6 | |
| 830. |
Consider the transmission line of length 37.5 cm, which is terminated into zero resistance. This line is being exited by a source of 1 GHz which has an internal impedance of 50 Ω. What is the input impedance of the line as seen by the source? |
| A. | 50 Ω |
| B. | Zero Ω |
| C. | 100 Ω |
| D. | Infinite Ω |
| Answer» E. | |
| 831. |
A super heterodyne receiver has a IF of 465 kHz. It is tuned to a station broadcasting at 500 KHz and its oscillator is operating at 965 KHz, then the 1330 KHz frequency would be |
| A. | adjacent channel frequency |
| B. | image frequency |
| C. | gyro frequency |
| D. | maximum usable frequency |
| Answer» C. gyro frequency | |
| 832. |
Consider the program segment written for 8085 based system:LXI S, FFFFHMVI A, 00HMVI B, 0FHSUB BCNC GOLOCMVI A, FFH where in the program subroutine labelled ''GOLOC'' introduces delay of 28 T-states only. How many T-states are required to execute above program statement? |
| A. | 41 |
| B. | 69 |
| C. | 44 |
| D. | Indeterminate |
| Answer» D. Indeterminate | |
| 833. |
How many maximum number of functions can be defined with two symbols which are Boolean in nature: |
| A. | 4 |
| B. | 8 |
| C. | 2 |
| D. | 16 |
| Answer» E. | |
| 834. |
Consider the system with and where p and q are arbitrary real numbers. Which of the following statements about the controllability of the system is true? |
| A. | The system is completely state controllable for any non zero values p and q |
| B. | Only p = 0 and q = 0 result in controllability |
| C. | The system is uncontrollable for all values of p and q |
| D. | We cannot conclude about controllability from the given data |
| Answer» D. We cannot conclude about controllability from the given data | |
| 835. |
Radiation efficiency of an antenna is defined as the ratio of |
| A. | Total power radiated by an antenna to the net power accepted by the antenna from the connected transmitter |
| B. | The frequency at which minimum power is radiated to the frequency at which maximum power is radiated |
| C. | Total power accepted from the transmitter to total power generated by the transmitter |
| D. | Power in main lobe to that in the side lobe |
| Answer» B. The frequency at which minimum power is radiated to the frequency at which maximum power is radiated | |
| 836. |
Find Vx Vy Vz |
| A. | Vx = -6 Vy = 3 Vz = -3 |
| B. | Vx = -6 Vy = -3 Vz = 1 |
| C. | Vx = 6 Vy = 3 Vz = 3 |
| D. | Vx = 6 Vy = 1 Vz = 3 |
| Answer» E. | |
| 837. |
What is the propagation constant for air filled wave guide with dimensions a = 1.59" and b = 0.795" at 4.95 GHz? |
| A. | 0.6698 |
| B. | 0.7698 |
| C. | 0.503 |
| D. | 0.6598 |
| Answer» B. 0.7698 | |
| 838. |
Which of the following oscillators is used for the generation of high frequencies? |
| A. | R-C phase shift oscillator |
| B. | Wien bridge oscillator |
| C. | L-C oscillator |
| D. | Blocking oscillator |
| Answer» D. Blocking oscillator | |
| 839. |
Consider the circuit shown below of 2 : 1 MUX is given by the function g = ac + bcThen f is |
| A. | X X |
| B. | XY + E X Y |
| C. | XE + XY |
| D. | None of these |
| Answer» C. XE + XY | |
| 840. |
A junction FET, can be used as a voltage variable resistor |
| A. | at pinch-off condition |
| B. | beyond pinch-off voltage |
| C. | well below pinch-off condition |
| D. | for any value of VDS |
| Answer» D. for any value of VDS | |
| 841. |
What are the minimum number of 2 to 1 multiplexers required to generate a 2 input AND gate a 2 input Ex-OR gate? |
| A. | 1 and 2 |
| B. | 1 and 3 |
| C. | 1 and 1 |
| D. | 2 and 2 |
| Answer» B. 1 and 3 | |
| 842. |
{ x(n) } is a real-valued periodic sequence with a period N. x(n) and X(k) form N-point. Discrete Fourier Transform (DFT) pairs. The DFT Y(k) of the sequence. y(n) = x(r) X (n + r) is |
| A. | |X(k)|2 |
| B. | X(r) X(k + r) |
| C. | 1 |
| D. | 0 |
| Answer» B. X(r) X(k + r) | |
| 843. |
The magnitude plot of a rational transfer function G(s) with real coefficients is shown below. Which of the following compensators has such a magnitude plot? |
| A. | Lead compensator |
| B. | Lag compensator |
| C. | PID compensator |
| D. | Lead-lag compensator |
| Answer» E. | |
| 844. |
The inverse of given Laplace transform is |
| A. | sin t |
| B. | cos t |
| C. | et |
| D. | e2t |
| Answer» C. et | |
| 845. |
A n-channel JFET has IDSS = 2 mA, Gate to source voltage VGS = - 2 V and trans-conductance is 0.5 mW then pinch-off voltage is __________ . |
| A. | - 2 V |
| B. | 2 V |
| C. | - 4 V |
| D. | 4 V |
| Answer» D. 4 V | |
| 846. |
The OP-AMP circuit shown above represents a |
| A. | high pass filter |
| B. | low pass filter |
| C. | band pass filter |
| D. | band reject filter |
| Answer» C. band pass filter | |
| 847. |
An audio signal is band limited to 4 kHz. It is sampled at 8 kHz. What will be the spectrum of the sampled signal? |
| A. | -4 kHz to 4 kHz |
| B. | -8 kHz to 8 kHz |
| C. | every 4n kHz repeating |
| D. | every ± 8 kHz and operating as well as at zero (k integer) |
| Answer» D. every ¬± 8 kHz and operating as well as at zero (k integer) | |
| 848. |
The depth of penetration at 4 MHz is 10 cm, then at 2.5 MHz it is |
| A. | 62.5 cm |
| B. | 13 cm |
| C. | 6.25 cm |
| D. | 8 cm |
| Answer» C. 6.25 cm | |
| 849. |
Which of the following does not cause losses in optical fibre cables? |
| A. | Impurities |
| B. | Microbending |
| C. | Attenuation in glass |
| D. | Stepped index operation |
| Answer» E. | |
| 850. |
The following circuit can be represented as : |
| A. | C |
| B. | f(A, B, C) = (0, 1, 2, 3, 4, 5, 6, 7) |
| C. | (A ‚äï B)C |
| D. | C |
| Answer» E. | |