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.
| 451. |
What is the purpose of DMA facility in microprocessor based system? |
| A. | To increase the speed of data transfer between the mP and the I/O devices |
| B. | To increase the speed of data transfer between the mP and the memory |
| C. | To increase the speed of data transfer between the memory and the I/O devices |
| D. | To improve the reliability of the system |
| Answer» D. To improve the reliability of the system | |
| 452. |
If x[n] = cos then the sequence x[n] is |
| A. | non-periodic |
| B. | periodic |
| C. | depends on n |
| D. | none of these |
| Answer» B. periodic | |
| 453. |
The circuit shown in the figure converts |
| A. | BCD to Binary code |
| B. | Binary to excess - 3 code |
| C. | Excess - 3 to Gray |
| D. | Gray to Binary |
| Answer» E. | |
| 454. |
Consider the following statements:In the case of space wave propagation, the signal strength at the receiver is Directly proportional to transmitter and receiver heights.Inversely proportional to distance between transmitter and receiver.Directly proportional to frequency. Which of the above statements is/are correct? |
| A. | 1 and 2 |
| B. | 1 and 3 |
| C. | 2 and 3 |
| D. | 3 only |
| Answer» C. 2 and 3 | |
| 455. |
F = ‚àë(0, 3, 4, 5, 7) = |
| A. | [B ‚äï C] + AC |
| B. | B'C' + BC + AC |
| C. | AB + BC + CA |
| D. | None |
| Answer» C. AB + BC + CA | |
| 456. |
Which of the following are the non-linear application of op-amp? Current-to-voltage converterComparatorPeak detectorLimiter Select the correct answer from the codes given below: |
| A. | 1, 2 and 3 |
| B. | 2, 3 and 4 |
| C. | 1, 3 and 4 |
| D. | 1, 2 and 4 |
| Answer» C. 1, 3 and 4 | |
| 457. |
In the given circuit, the switch has been in position 1 for quite a long time. At t = 0 the switch is moved to position 2. At this position what is the time constant? |
| A. | 0.1 s |
| B. | 1 s |
| C. | 0.11 s |
| D. | 1.11 s |
| Answer» B. 1 s | |
| 458. |
Which of the following terms are equivalent? A ‚äï B ‚äï CA ‚äï B ‚äô C A ‚äô B ‚äï CA ‚äô B ‚äô C |
| A. | 1 and 4; 2 and 3 |
| B. | 1 and 3 |
| C. | 2 and 3 |
| D. | 1, 2 and 4 |
| Answer» B. 1 and 3 | |
| 459. |
A balanced modulator is used in the generation of which of the following? |
| A. | DSB-SC signal |
| B. | FM signal |
| C. | PM signal |
| D. | PAM signal |
| Answer» B. FM signal | |
| 460. |
In a CMOS CS amplifier, the active load is obtained by connecting a |
| A. | p channel current mirror circuit |
| B. | n channel transistor |
| C. | p channel transistor |
| D. | BJT current mirror |
| Answer» B. n channel transistor | |
| 461. |
What is the purpose of a start in RS232 serial communication protocol? |
| A. | To synchronise receiver for receiving every byte |
| B. | To synchronise receiver for receiving a sequence of byte |
| C. | Acts as a parity bit |
| D. | To synchronise receiver for receiving the last byte |
| Answer» B. To synchronise receiver for receiving a sequence of byte | |
| 462. |
An FM transmitter delivers 80W to a load of 30 W when no modulation is present. The carrier is now frequency modulated by a single sinusoidal signal and the peak frequency deviation is so adjusted to make the amplitude of the second sideband is zero in the given output.J0(0, 0) = 1, J0(2, 4) = 0, J0(3.8) = - 0.4, J0(5.1)= - 0.1J1(2, 4) = 0.52, J1((3.8) = 0, J1(5.1) = - 0.33, J2(2.4) = 0.1J2(3.8)= 0.41, J2(5.1) = 0Power in the first order sidebands is : |
| A. | 5.12 W |
| B. | 21.78 W |
| C. | 2.56 W |
| D. | 16.81 W |
| Answer» C. 2.56 W | |
| 463. |
A short vertical grounded antenna is required to radiate at 1 MHz. The effective height of the antenna is 302 m. The calculated value of radiation resistance is |
| A. | 1.58 Ω |
| B. | 158 Ω |
| C. | 15.8 Ω |
| D. | none |
| Answer» D. none | |
| 464. |
For a bipolar transistor, avalanche multiplication factor depends on __________ . |
| A. | VCE |
| B. | VCB |
| C. | VBE |
| D. | none of these |
| Answer» C. VBE | |
| 465. |
Which is the dominant mode in rectangular waveguides? |
| A. | TE10 |
| B. | TE11 |
| C. | TE01 |
| D. | TM11 |
| Answer» B. TE11 | |
| 466. |
Unit doublet is the Laplace inverse of __________ . |
| A. | 1/s |
| B. | s2 |
| C. | s |
| D. | none of these |
| Answer» D. none of these | |
| 467. |
How many roots with positive real parts do the equation s3 + s2 - s + 1 = 0 have? |
| A. | Zero |
| B. | One |
| C. | Two |
| D. | Three |
| Answer» D. Three | |
| 468. |
Thin gate oxide in a CMOS process in preferably grown using |
| A. | wet oxidation |
| B. | dry oxidation |
| C. | epitaxial deposition |
| D. | ion implantation |
| Answer» B. dry oxidation | |
| 469. |
The range of memory location in given memory interfacing scheme is |
| A. | 0000H - 07FFH |
| B. | F800H - FFFFH |
| C. | 0000H - 03FFH |
| D. | 0000H - 3FFFH |
| Answer» C. 0000H - 03FFH | |
| 470. |
In the design of a single mode step index optical fiber close to upper cut-off, the single mode operations is NOT preserved if |
| A. | radius as well as operating wavelength are halved |
| B. | radius as well as operating wavelength are doubled |
| C. | radius is halved and operating wavelength is doubled |
| D. | radius is doubled and operating wavelength is halved |
| Answer» C. radius is halved and operating wavelength is doubled | |
| 471. |
Which of the following algorithms design techniques is used in quick sort algorithm? |
| A. | Dynamic programming |
| B. | Backtracking |
| C. | Divide and conquer |
| D. | Greedy |
| Answer» D. Greedy | |
| 472. |
To realize following function 'f'How many minimum number of 2 input NAND gates are required? |
| A. | 3 |
| B. | 6 |
| C. | 4 |
| D. | 10 |
| Answer» E. | |
| 473. |
For parallel plane waveguides, which is the mode with lowest cut-off frequency? |
| A. | TE10 |
| B. | TM10 |
| C. | TEM |
| D. | TE11 |
| Answer» B. TM10 | |
| 474. |
The analog signal given below is sampled by 600 samples per secondm(t) = 2 sin 480pt + 3 sin 720ptThe folding (maximum) frequency is __________ . |
| A. | 600 Hz |
| B. | 120 Hz |
| C. | 300 Hz |
| D. | 360 Hz |
| Answer» D. 360 Hz | |
| 475. |
The driving point impedance of the following network is given by . The component values are |
| A. | L = 5H, R = 0.5Ω, C = 0.1F |
| B. | L = 0.1H, R = 0.5Ω, C = 5F |
| C. | L = 5H, R = 2Ω, C = 0.1F |
| D. | L = 0.1H, R = 2Ω, C = 5F |
| Answer» B. L = 0.1H, R = 0.5Œ©, C = 5F | |
| 476. |
A 2 μF capacitor is shunted by a 1 kΩ maintained at temperature 400 K. The rms noise voltage across the capacitor over the entire frequency band is: |
| A. | 6.25 x 10-8 V |
| B. | 5.25 x 10-6 V |
| C. | 6.25 x 10-6 V |
| D. | 5.25 x 10-8 V |
| Answer» E. | |
| 477. |
How many and which types of machine cycles are needed to execute PUSH PSW by 8085 microprocessor? |
| A. | 2, Fetch and memory write |
| B. | 3, Fetch and memory write |
| C. | 3, Fetch and memory read |
| D. | 3, Fetch and memory read and memory write |
| Answer» B. 3, Fetch and memory write | |
| 478. |
Assertion (A): A z-directed rectangular waveguide with cross-sectional dimensions 3 cm x 1 cm will support propagation at 4 GHz.Reason (R): where λ is the wavelength. |
| 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» E. | |
| 479. |
4 point DFT for x(n) = {2, - 1, 2, 3} is |
| A. | {6, 4 - 2j, 2, 2j} |
| B. | {6, 4j, 2, - 4j} |
| C. | {6, -1 + 3j, 4 - 4j, 4 - 2} |
| D. | {6, 2j, 4 - 2j, - 2 + 2j} |
| Answer» C. {6, -1 + 3j, 4 - 4j, 4 - 2} | |
| 480. |
In a microprocessor, the service routine for a certain interrupt starts from a fixed location of memory which cannot be externally set, but the interrupt can be delayed or rejected. Such an interrupt is |
| A. | non-maskable and non-vectored |
| B. | maskable and non-vectored |
| C. | non-maskable and non-vectored |
| D. | maskable and vectored |
| Answer» E. | |
| 481. |
Assertion (A): A rectifier with inductor filter is more efficient for high load current.Reason (R): In rectifier with inductor filter we can use a larger choke to reduce ripple, larger choke will have higher dc resistance which will result in lower dc output voltage for higher load current. |
| 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» B. Both A and R are individually true but R is not the correct explanation of A | |
| 482. |
The Boolean function realized by the logic circuit shown is |
| A. | F = Σm(0, 1, 3, 5, 9, 10, 14) |
| B. | F = Σm(2, 3, 5, 7, 8, 12, 13) |
| C. | F = Σm(1, 2, 4, 5, 11, 14, 15) |
| D. | F = Σm(2, 3, 5, 7, 8, 9, 12) |
| Answer» E. | |
| 483. |
Simplify : A + B + A B + (A + B)AB + C(B + AB) |
| A. | B + A |
| B. | C |
| C. | C |
| D. | 1 |
| Answer» B. C | |
| 484. |
For a system with transfer function The bandwidth of the system is (rad/sec) |
| A. | 2.828 |
| B. | 5.2915 |
| C. | 5.088 |
| D. | cannot be determined |
| Answer» D. cannot be determined | |
| 485. |
A certain JK FF has tpd = 12 nsec. The largest MOD counter that can be constructed from these FFs and still operate up to 10 MHz is |
| A. | any |
| B. | 8 |
| C. | 256 |
| D. | 10 |
| Answer» C. 256 | |
| 486. |
The number of open right half plane poles of is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 487. |
In an n-type silicon crystal at room temperature, which of the following can have a concentration of 4 x 1019 cm-3? |
| A. | Silicon atoms |
| B. | Holes |
| C. | Dopant atoms |
| D. | Valence electrons |
| Answer» D. Valence electrons | |
| 488. |
In a infinite ladder circuit as shown above each resistance of r Ω then find RAB |
| A. | ‚àû |
| B. | |
| C. | 1.61r |
| Answer» D. | |
| 489. |
What is the approximate steady state current in the above circuit? |
| A. | 50 A |
| B. | 25 A |
| C. | 0.20833333333333 |
| D. | 0.041666666666667 |
| Answer» D. 0.041666666666667 | |
| 490. |
Figure below shows D type Flip-Flops connected as shift register, then outputs QD, QC, QB, QA are given by: |
| A. | 1 and 2 only |
| B. | 2 and 3 only |
| C. | 1, 2 and 3 |
| D. | none of these |
| Answer» E. | |
| 491. |
Consider the following statements: With increase in temperature Fermi-level tries to come in between the energy gap exactly at middle Mobility of electron in GaAs is very high compared to mobility of holeIn LED, the light energy radiated due to recombination with the aid of traps. Which of these statements are true? |
| A. | 1 and 2 |
| B. | 1, 2 and 3 |
| C. | 2 and 3 |
| D. | 1 and 3 |
| Answer» B. 1, 2 and 3 | |
| 492. |
What is the frequency of pulse at the points a, b, c in the circuit? |
| A. | 3 MHz |
| B. | 7.8 KHz |
| C. | 10 KHz |
| D. | 1 MHz |
| Answer» C. 10 KHz | |
| 493. |
A function of one of more variables which conveys information on the nature of physical phenomenon is called |
| A. | Noise |
| B. | Interference |
| C. | System |
| D. | Signal |
| Answer» E. | |
| 494. |
A 1000 kHz carrier wave modulated 40% at 4000 Hz is applied to a resonant circuit tuned to a carrier frequency and having Q = 140. What is the degree of modulation after transmission through this circuit? |
| A. | 0.4 |
| B. | 0.2 |
| C. | 0.27 |
| D. | 0.54 |
| Answer» D. 0.54 | |
| 495. |
Voltage 1 + 2 sin ωt is applied to the circuit shown below:The capacitor C and diode D can be considered ideal. RL is very large resistance. Then the magnitude of the average voltage across RL is __________ volt. |
| A. | 0 volt |
| B. | 2 volts |
| C. | -2 volts |
| D. | -3 volts |
| Answer» D. -3 volts | |
| 496. |
A signal with ± 10 V ranged and 1 KHz band width is being digitized using a sample and hold circuit and a 10 bit quantizer. The quantization step is : |
| A. | 1 x 10-9 V |
| B. | 5 x 10-9 V |
| C. | 2.5 x 10-9 V |
| D. | 0.5 x 10-9 V |
| Answer» E. | |
| 497. |
In a series operated thyristor configuration, each thyristor should support 100 V. However, the three thyristors only support voltage of 100 V, 90 V and 85 V respectively. Hence, the string efficiency in the case is : |
| A. | 0.9845 |
| B. | 0.4584 |
| C. | 0.9167 |
| D. | none of these |
| Answer» D. none of these | |
| 498. |
A 4 cm by 3 cm rectangular waveguide with air cavity, is operating at 12 GHz with TE11 mode. The cut-off frequency is: |
| A. | 6.25 GHz |
| B. | 4.75 GHz |
| C. | 1.5 GHz |
| D. | 8.75 GHz |
| Answer» B. 4.75 GHz | |
| 499. |
In the circuit shown in the given figure the diode states at the extremely large negative values of the input voltage vi are : |
| A. | D1 off, D2 off |
| B. | D1 on, D2 off |
| C. | D1 off, D2 on |
| D. | D1 on, D1 on, D2 on |
| Answer» C. D1 off, D2 on | |
| 500. |
Hari (H), Gita (G), Irfan (I) and Saira (S) are sibiligs (i.e. brothers and sisters). All were born on 1st January. The age difference between any two successive siblings (that is born one after another) is less than 3 years. Given the following facts:(i) Hari's age + Gita's age > Irfan's age + Saira's age.(ii) The age difference between Gita and Saira is 1 year. However, Gita is not the oldest and Saira is not the youngest.(iii) There are not twins.In what order were they born (Oldest first)? |
| A. | HSIG |
| B. | SGHI |
| C. | IGSH |
| D. | IHSG |
| Answer» C. IGSH | |