MCQOPTIONS
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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.
| 851. |
Consider the following statements a half adder. As a half subtractor alsohas two outputs CH = x x y and Sn = x ‚äï y for two inputs x and yhas two outputs CH = x + y and SH = x ‚äï y for two inputs x and yis a combinational circuit Which of the statements given above is/are correct? |
| A. | 1, 3, 4 |
| B. | 1, 2, 4 |
| C. | 4 only |
| D. | 2 and 3 |
| Answer» C. 4 only | |
| 852. |
Rank of the matrix: |
| A. | 3 |
| B. | 2 |
| C. | 1 |
| D. | 4 |
| Answer» D. 4 | |
| 853. |
Consider the differential amplifier shown in figure. (Assume β is very high).VC = |
| A. | 5 V |
| B. | 10 V |
| C. | 15 V |
| D. | 30 V |
| Answer» C. 15 V | |
| 854. |
The circuit shown below is the equivalent circuit of which one of the following microwave resonator types? |
| A. | Butterfly resonator |
| B. | Parallel-wire resonator |
| C. | Cavity resonator |
| D. | Coaxial line resonator |
| Answer» B. Parallel-wire resonator | |
| 855. |
In the following network, the switch is closed at t = 0 and the sampling starts from t = 0. The sampling frequency is 10Hz.The samples x(n) (n = 0, 1, 2, ...) are given by |
| A. | 5(1 - e-0.05n) |
| B. | 5e-0.05n |
| C. | 5(1 - e-5n) |
| D. | 5e-5n |
| Answer» C. 5(1 - e-5n) | |
| 856. |
The circuit shown in the figure has 4 boxes each described by inputs P, Q, R and outputs Y, Z withY = P ‚äï Q ‚äï R, Z = RQ + P R + Q PThe circuit is a |
| A. | 4 bit adder giving P + Q |
| B. | 4 bit subtractor giving P - Q |
| C. | 4 bit subtractor giving Q - P |
| D. | 4 bit adder giving P + Q + R |
| Answer» C. 4 bit subtractor giving Q - P | |
| 857. |
Which of the following stages has no phase inversion of the signal? |
| A. | Two CE stages |
| B. | Three CE stages |
| C. | CE and CC stages |
| D. | CE stage and emitter follower |
| Answer» B. Three CE stages | |
| 858. |
Which of the following meters cannot measure a.c. quantities? |
| A. | Thermocouple |
| B. | Hot wire |
| C. | P.M.M.C. |
| D. | Electrodynamometer. |
| Answer» D. Electrodynamometer. | |
| 859. |
The pole-zero plot given below corresponds to a |
| A. | low pass filter |
| B. | high pass filter |
| C. | band pass filter |
| D. | notch filter |
| Answer» D. notch filter | |
| 860. |
25 persons are in a room. 15 of them play hockey, 17 of them play football and 10 of them play both hockey and football. Then the number of persons playing neither hockey nor football is: |
| A. | 2 |
| B. | 17 |
| C. | 13 |
| D. | 3 |
| Answer» E. | |
| 861. |
The maximum percent overshoot with maximum value of first overshoot as 3.5 V and steady state value as 2.575 V is |
| A. | 0.3592 |
| B. | 0.2643 |
| C. | 0.5761 |
| D. | 0.1524 |
| Answer» B. 0.2643 | |
| 862. |
The fuse material used in electrical lines must have which one of the following properties? |
| A. | High resistivity |
| B. | Low conductivity |
| C. | High melting point |
| D. | Low melting point |
| Answer» E. | |
| 863. |
In the given figure.The damped frequency is __________ . |
| A. | 0 rad/sec |
| B. | 2 rad/sec |
| C. | 3/2 rad/sec |
| D. | None of these |
| Answer» D. None of these | |
| 864. |
An 8 level encoding scheme is used in a PCM system of 10 kHz channel BW. The channel capacity is |
| A. | 80 kbps |
| B. | 60 kbps |
| C. | 30 kbps |
| D. | 18 kbps |
| Answer» C. 30 kbps | |
| 865. |
A 16 bit type ADC uses 1 MHz clock its maximum conversion time is __________ . |
| A. | 16 μs |
| B. | 15 ms |
| C. | 6.5 ms |
| D. | 66 ms |
| Answer» D. 66 ms | |
| 866. |
The circuits with active pull up are preferred because of their stability for |
| A. | wired - AND operation |
| B. | wired - OR operation |
| C. | bus operated system |
| D. | reasonable dissipation and speed of operation |
| Answer» B. wired - OR operation | |
| 867. |
Consider the following network functionIn order to make N(s) as rational network function, it is essential to include |
| A. | zero at origin |
| B. | zero at infinity |
| C. | pole at origin |
| D. | pole at infinity |
| Answer» C. pole at origin | |
| 868. |
Consider the following amplifier with negative feedbackIf the closed loop gain of above amplifier is + 100, the value of β will be |
| A. | -9 x 10-3 |
| B. | 9 x 10-3 |
| C. | -11 x 10-3 |
| D. | 11 x 10-3 |
| Answer» B. 9 x 10-3 | |
| 869. |
The following circuit diagram resembles : |
| A. | logic 0 |
| B. | logic 1 |
| C. | f(A, B, C)= m(0, 1, 4, 6, 7) |
| D. | None of these |
| Answer» C. f(A, B, C)= m(0, 1, 4, 6, 7) | |
| 870. |
The system shown in figure remains stable when : |
| A. | k £ - 1 |
| B. | #NAME? |
| C. | l < k < 3 |
| D. | k > 3 |
| Answer» E. | |
| 871. |
What are the values of Emax and Emin displayed on the oscilloscope, when a 1 kV P-P carries is modulated to 50%? |
| A. | 2 kV, 0.5 kV |
| B. | 1 kV, 0.5 kV |
| C. | 0.75 kV, 0.25 kV |
| D. | 0.5 kV, 1.5 kV |
| Answer» D. 0.5 kV, 1.5 kV | |
| 872. |
In a semiconductor material. The hole concentration is found to be 2 x 2.5 x 1015 cm-3. If mobility of carriers is 0.13 m2/ v-s. Then find the current density if electric field intensity is 3.62 x 10-19 |
| A. | 7.6237 x 10-4 A/cm2 |
| B. | 7.6237 x 10-5 A/cm2 |
| C. | 7.6237 x 10-3 A/cm2 |
| D. | none of these |
| Answer» B. 7.6237 x 10-5 A/cm2 | |
| 873. |
The resolution of a DAC depends on which of the following? |
| A. | The number of bits |
| B. | Monotonicity |
| C. | Reference voltage |
| D. | The values of resistance |
| Answer» B. Monotonicity | |
| 874. |
A radar receiver has a noise figure of 10 dB at 300 K having a bandwidth of 2.5 MHz. The minimum power it can receive is |
| A. | 3.45 x 10-15 W |
| B. | 1.38 x 10-15 W |
| C. | 7.5 x 10-15 W |
| D. | 93.15 x 10-15 W |
| Answer» E. | |
| 875. |
Consider the following Maximum energy of electrons liberated photoelectrically is independent of light intensityMaximum energy of electrons liberated photoelectrically varies nonlinearly with frequency of incident light. |
| A. | (1) is true and (2) is false |
| B. | (1) and (2) both are true |
| C. | (1) is false and (2) is true |
| D. | (1) and (2) both are false |
| Answer» B. (1) and (2) both are true | |
| 876. |
The minimum energy of a photon required for intrinsic excitation is equal to |
| A. | energy of bottom of conduction band |
| B. | energy of top of valence band |
| C. | forbidden gap energy |
| D. | Fermi energy |
| Answer» D. Fermi energy | |
| 877. |
If X = 1 in the logic equation [X + Z { Y + (Z + X Y)}] { X + Z (X + Y)} = 1, then |
| A. | Y = Z |
| B. | Y = Z |
| C. | Z = 1 |
| D. | Z = 0 |
| Answer» E. | |
| 878. |
For a = - 1, find the value of V2 |
| A. | ‚àû |
| B. | 0 |
| C. | V1 |
| D. | none of the above |
| Answer» C. V1 | |
| 879. |
Assertion (A): The expression E = - ΔV, where E is the electric field and V is the potential is not valid for time varying fields.Reason (R): The curl of a gradient is identically zero. |
| A. | Both A and R are individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 880. |
The circuit given below is: |
| A. | Band stop filter |
| B. | Band pass filter |
| C. | Oscillator circuit |
| D. | All pass filter |
| Answer» C. Oscillator circuit | |
| 881. |
A certain 8 bit uniform quantization PCM system can accommodate a signal ranging from - 1 V to + V. The rms value of the signal is V . The signal to quantization noise ratio is: |
| A. | 30 dB |
| B. | 46.91 dB |
| C. | 40 dB |
| D. | 49.92 dB |
| Answer» E. | |
| 882. |
The electric field of 2.5 x 107 V/m can give 1 eV energy to condition electron, then in a copper block what will be the mean free path of electron? |
| A. | 5 x 10-8 m |
| B. | 4 x 10-7 m |
| C. | 0.4 m |
| D. | 0.5 m |
| Answer» C. 0.4 m | |
| 883. |
A rectangular waveguide, in dominant TE mode, has dimensions 10 cm x 15 cm. The cut off frequency is |
| A. | 10 GHz |
| B. | 1 GHz |
| C. | 15 GHz |
| D. | 25 GHz |
| Answer» C. 15 GHz | |
| 884. |
Find 'X' in the circuit below :f1(A, B, C, D) = Σ(6, 7, 13, 14);f2(A, B, C, D) = Σ(3, 6, 7);f3(A, B, C, D) = Σ(5, 6, 7, 14, 15) |
| A. | p(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15) |
| B. | 0 |
| C. | Σ(14) |
| D. | 1 |
| Answer» D. 1 | |
| 885. |
Determine the potential difference between the points A and B in the steady state |
| A. | 40 V |
| B. | 60 V |
| C. | 25 V |
| D. | 75 V |
| Answer» E. | |
| 886. |
A transmission line has a characteristic impedance of 50 Ω and a resistance of 0.1 Ω/m, if the line is distortion less, the attenuation constant (in Np/m) is |
| A. | 500 |
| B. | 5 |
| C. | 0.014 |
| D. | 0.002 |
| Answer» E. | |
| 887. |
If x[n] then the sequence x[n] is |
| A. | non-periodic |
| B. | periodic |
| C. | depends on n |
| D. | none of these |
| Answer» B. periodic | |
| 888. |
Which of the following uses 'transferred electron effect' for production of microwaves? |
| A. | Silicon |
| B. | Germanium |
| C. | Metal-semiconductor junction |
| D. | Gallium Arsenide |
| Answer» E. | |
| 889. |
Following state diagram shows clocked sequential circuit: How many states the sequential circuit has? |
| A. | 6 |
| B. | 7 |
| C. | 5 |
| D. | 4 |
| Answer» D. 4 | |
| 890. |
The ratio of the diffusion coefficient in a semiconductor has the units |
| A. | V-1 |
| B. | em.V-1 |
| C. | V.cm-1 |
| D. | V.s |
| Answer» B. em.V-1 | |
| 891. |
In the signal flow graph of figure below, the gain C/R will be : |
| A. | 43719 |
| B. | 22/15 |
| C. | 24/23 |
| D. | 44/23 |
| Answer» E. | |
| 892. |
In a communication system, a process in which statistical averages and time averages are equal is called as, |
| A. | stationary |
| B. | ergodic |
| C. | Gaussian |
| D. | BIBO stable |
| Answer» C. Gaussian | |
| 893. |
Px(X) = M exp(- 2 |x|) + N exp(- 3 |x|) is the probability density function for the real random variable X, over the entire x axis. M and N are both positive real numbers. The equation relating M and N is |
| A. | |
| B. | |
| Answer» B. | |
| 894. |
Radiation resistance of an antenna is 54 Ω and loss resistance is 6 Ω. If antenna has power gain of 10, then directivity is: |
| A. | 9 |
| B. | 11.11 |
| C. | data not sufficient |
| D. | 10 |
| Answer» C. data not sufficient | |
| 895. |
If RT, Rh represent condition for reciprocity in case of transmission parameter and hybrid parameter respectively and similarly ST, Sh represent condition for symmetry in case of transmission parameter and hybrid parameter respectively then match the following :(1) RT (a) A = D(2) Rh (b) h12 = h21(3) ST (c) AD - BC = 1(4) Sh (d) h12 = - h21 (e) B = c (f) Δh = 1 |
| A. | 1 - c 2 - d 3 - a 4 - f |
| B. | 1 - c 2 - b 3 - e 4 - d |
| C. | 1 - e 2 - d 3 - a 4 - b |
| D. | 1 - e 2 - d 3 - a 4 - f |
| Answer» B. 1 - c 2 - b 3 - e 4 - d | |
| 896. |
If we manage to __________ our natural resources, we would leave a better planet for our children. |
| A. | uphold |
| B. | restrain |
| C. | Cherish |
| D. | conserve |
| Answer» E. | |
| 897. |
A lossless 50 Ω transmission line is terminated 30 + j25 Ω, then voltage reflection coefficient and current reflection coefficient are |
| A. | 062 ∠82.88, - 0.62 ∠82.88 |
| B. | 10.36 ∠11.296, - 10.36 ∠111.296 |
| C. | 0.23 ∠49.1, - 0.23 ∠ + 49.1 |
| D. | - 10.36 ∠111.296, 10.36 ∠111.296 |
| Answer» E. | |
| 898. |
A single mode fibre not suffer from which type of dispersion? |
| A. | Waveguide dispersion |
| B. | Material dispersion |
| C. | Intermodal dispersion |
| D. | Polarization mode dispersion |
| Answer» D. Polarization mode dispersion | |
| 899. |
A ramp input applied to a unity feedback system results in 5% steady state error. The type number and zero frequency gain of the system are respectively. |
| A. | 1 and 20 |
| B. | 0 and 20 |
| C. | 0 and 1/20 |
| D. | 1 and 1/20 |
| Answer» B. 0 and 20 | |
| 900. |
In the circuit shown, in switch S is open for a long time and is closed at t = 0. The current i(t) for t ‚â• 0+ is |
| A. | i(t) = 0.5 - 0.125e-1000t A |
| B. | i(t) = 1.5 - 0.125e-1000t A |
| C. | i(t) = 0.5 - 0.5e-1000t A |
| D. | i(t) = 0.375e-1000t A |
| Answer» B. i(t) = 1.5 - 0.125e-1000t A | |