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.
| 1. |
For a standard 2nd order system the maximum overshoot is 10% to an unit step input. If the magnitude of the input is doubled, then maximum overshoot and percentage of maximum overshoot is: |
| A. | maximum overshoot doubles and percentage of maximum overshoot is less than double |
| B. | maximum overshoot doubles and percentage of maximum overshoot do not change |
| C. | maximum overshoot remain same and percentage of maximum overshoot is double |
| D. | maximum overshoot more than double and percentage of maximum overshoot is less than double |
| Answer» C. maximum overshoot remain same and percentage of maximum overshoot is double | |
| 2. |
The number of distinct Boolean expressions of 3 variables is |
| A. | 8 |
| B. | 256 |
| C. | 64 |
| D. | 7 |
| Answer» C. 64 | |
| 3. |
A DC voltage source is connected across a series R - L - C circuit. Under steady-state conditions, the applied DC voltage drops entirely across the |
| A. | R only |
| B. | C only |
| C. | L only |
| D. | R and L combination |
| Answer» C. L only | |
| 4. |
If (225)Y = (165)8 find value of Y |
| A. | 7 |
| B. | 8 |
| C. | 9 |
| D. | 11 |
| Answer» B. 8 | |
| 5. |
If A = then |A50| will be |
| A. | (1 - 1002) |
| B. | (1 - 502) |
| C. | (1 - 1002) |
| D. | (1 - 502) |
| Answer» C. (1 - 1002) | |
| 6. |
An LTI system having transfer function and input x(t) = sin (t + 1) is in steady state. The output is sampled at a rate ωs rad/s to obtain the final output {y(k)}. Which of the following is true? |
| A. | y(.) is zero for all sampling frequencies ωs |
| B. | y(.) is nonzero for all sampling frequencies ωs |
| C. | y(.) is nonzero for ωs > 2, but zero for ωs > 2 |
| D. | y(.) is zero for ωs > 2 but nonzero for ωs > 2 |
| Answer» B. y(.) is nonzero for all sampling frequencies œâs | |
| 7. |
The feedback control system shown in figure is stable. |
| A. | for all K ‚â• 0 |
| B. | only if K ‚â• 1 |
| C. | only if 0 ≤ K < 1 |
| D. | only if -1 ≤ K < 1 |
| Answer» D. only if -1 ‚⧠K < 1 | |
| 8. |
Assertion (A): Conductors do not permit propagation of waves more than a short distance into the conductor at microwave frequencies.Reason (R): The relaxation time constant for conductors is much small than the period of centimetric EM wave. |
| A. | Both (A) and (R) are true and (R) is the correct explanation of (A) |
| B. | Both (A) and (R) are 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 | |
| 9. |
What are the counting stages (Q1, Q2) for the counter shown in the figure below? |
| A. | 11, 10, 00, 11, 10, ... |
| B. | 01, 10, 11, 00, 10, ... |
| C. | 00, 11, 01, 10, 00, ... |
| D. | 01, 10, 00, 01, 10, ... |
| Answer» B. 01, 10, 11, 00, 10, ... | |
| 10. |
Two coils X of 1000 turns and Y of 2000 turns are placed such that 60% of the flux produced by coil X links coil Y. A current of 1 A in coil X produces 0.1 wb flux. The mutual inductance between coils is |
| A. | 0.12 H |
| B. | 0.08 H |
| C. | 0.06 H |
| D. | 0.04 H |
| Answer» B. 0.08 H | |
| 11. |
Find RL for maximum power transfer. |
| A. | 3 Ω |
| B. | 1.125 Ω |
| C. | 4.1785 Ω |
| D. | None of these |
| Answer» B. 1.125 Œ© | |
| 12. |
Consider the sequence x(n) whose fourier transform X(ejω) is depicted for - p ≤ ω ≤ p as shown in figure x(n) is periodicRealEvenFinite energy |
| A. | 1 - True, 2 - True, 3 - True, 4 - True |
| B. | 1 - False, 2 - True, 3 - False, 4 - True |
| C. | 1 - True, 2 - False, 3 - True, 4 - False |
| D. | 1 - False, 2 - False, 3 - False, 4 - True |
| Answer» C. 1 - True, 2 - False, 3 - True, 4 - False | |
| 13. |
ωL = |
| A. | 108 rad/sec |
| B. | 104 rad/sec |
| C. | 102 rad/sec |
| D. | 10 rad/sec |
| Answer» E. | |
| 14. |
The characteristic polynomial of a system is q(s) = 2s5 + s4 + 4s3 + 2s2 + 1. The system is : |
| A. | stable |
| B. | marginally stable |
| C. | unstable |
| D. | oscillatory |
| Answer» D. oscillatory | |
| 15. |
The region between a pin of parallel perfectly conducting planes of infinite extent is y and z directions is partially filled with a dielectric as shown below.A 30 GHz TE10 wave is incident on the air-dielectric interface. The VSWR at the interface is |
| A. | -2 |
| B. | 2 |
| C. | 0 |
| D. | 1 |
| Answer» C. 0 | |
| 16. |
The number of essential prime implicant for the logic expression F = ABC + C D A + CDA + ABC + BD |
| A. | 3 |
| B. | 5 |
| C. | 4 |
| D. | 6 |
| Answer» B. 5 | |
| 17. |
The electric field of uniform plane wave is given by E = 20 sin (2 p x 108t- pz) x + 20 cos (2 p x 108t - pz) y. Find phase velocity |
| A. | 2 x 108 m/s |
| B. | p x 108 m/s |
| C. | 2p x 108 m/s |
| D. | none of these |
| Answer» B. p x 108 m/s | |
| 18. |
VR at t < T, t = ‚àû |
| A. | 500e-40x104t, 0 |
| B. | 100e-40x103t, 0 |
| C. | 100e-40x106t, 0 |
| D. | 100e-40x104t, 0 |
| Answer» E. | |
| 19. |
In the following transistor circuit VBE = 0. 7 V, rc = 25mV/IE, and β and the capacitance are very largeThe mid-band voltage gain of the amplifier is approximately |
| A. | -180 |
| B. | -120 |
| C. | -90 |
| D. | -60 |
| Answer» E. | |
| 20. |
Which of the following is a microwave power amplifier? |
| A. | Gunn diode |
| B. | Reflex klystron |
| C. | Magnetron |
| D. | Travelling wave tube |
| Answer» E. | |
| 21. |
The feedback control system shown in the given figure represents |
| A. | Type 0 system |
| B. | Type 1 system |
| C. | Type 2 system |
| D. | Type 3 system |
| Answer» E. | |
| 22. |
In the circuit shown, the power supplied by the voltage source |
| A. | 0 W |
| B. | 5 W |
| C. | 10 W |
| D. | 100 W |
| Answer» B. 5 W | |
| 23. |
A bipolar differential amplifier uses a transistor having β0 = 200, ICQ = 100 mA, |Adm| = 500 and CMRR = 80 dB. The value of Rc and RE will be respectively __________ . |
| A. | 1.25 kΩ, 1.25 MΩ |
| B. | 125 kΩ, 1.25 MΩ |
| C. | 1.25 MΩ, 1.25 kΩ |
| D. | 3.25 kΩ, 3.25 MΩ |
| Answer» B. 125 kŒ©, 1.25 MŒ© | |
| 24. |
The amplifier network is shown below: re and z0 is: |
| A. | 6.42 kΩ, 5.6 kΩ |
| B. | 6.42 Ω, (5.62) kΩ |
| C. | 6.4kΩ, (5.62) kΩ |
| D. | 6.42 Ω, 5.6 kΩ |
| Answer» E. | |
| 25. |
Consider two random processes x(t) and y(t) have zero mean, and they are individually stationary. The random process is z(t) = x(t) + y(t). Now when stationary processes are uncorrelated then power spectral density of z(t) is given by |
| A. | Sx(f) + Sy(f) + 2Sxy(f) |
| B. | Sx(f) + Sy(f) + 2Sxy(f) + 2Syx(f) |
| C. | Sx(f) + Sy(f) |
| D. | Sx(f) + Sy(f) - 2Sxy(f) - 2Syx(f) |
| Answer» D. Sx(f) + Sy(f) - 2Sxy(f) - 2Syx(f) | |
| 26. |
A standard waveguide W R90 has inside wall dimensions of a = 2.286 cm and b = 1.016 cm. What is the cut-off wavelength for TE01 mode? |
| A. | 4.572 cm |
| B. | 2.286 cm |
| C. | 2.032 cm |
| D. | 1.857 cm |
| Answer» D. 1.857 cm | |
| 27. |
An 8085 executes the following instructions2710 LXI H, 30A0H2713 DAD H2714 PCHLAll addresses and constants are in Hex. Let PC be the contents of the program counter and HL be the contents of the HL register pair just after executing PCHL.Which of the following statements is correct? |
| A. | PC = 2715 H HL = 30A0 H |
| B. | PC = 30A0H HL = 2715H |
| C. | PC = 6104 H HL = 6140 H |
| D. | PC = 6140H HL = 2715H |
| Answer» D. PC = 6140H HL = 2715H | |
| 28. |
In the circuit s closed for a long time and steady state is reached. s is opened at t = 0+ Determine current through resistor. |
| A. | A |
| B. | A |
| C. | #NAME? |
| D. | #NAME? |
| Answer» C. #NAME? | |
| 29. |
The transfer function of a zero-order-hold system is : |
| A. | (l/s)(l + e-sT) |
| B. | (1/s)(1 - e-sT) |
| C. | 1 - (l/s)e-sT |
| D. | 1 + (1/s)e-sT |
| Answer» C. 1 - (l/s)e-sT | |
| 30. |
A speech signal, band limited to 4kHz and peak voltage varying between + 5V and - 5V is sampled at the Nyquist rate. Each sample is quantized and represented by 8 bits. If the bits 0 and 1 are transmitted using bipolar pulses, the minimum bandwidth required for distortion free transmission is |
| A. | 64 kHz |
| B. | 32 kHz |
| C. | 8 kHz |
| D. | 4 kHz |
| Answer» E. | |
| 31. |
The probability density function of the envelope of narrow band noise is : |
| A. | Uniform |
| B. | Gaussian |
| C. | Rayleigh |
| D. | None |
| Answer» C. Rayleigh | |
| 32. |
If (10) x x(10)x = (100)x; (100)x x (100)x = (10000)x then x can take value |
| A. | 2 |
| B. | 5 |
| C. | 10 |
| D. | All |
| Answer» E. | |
| 33. |
Find current flowing through 1 H inductor at t = 0, at which switch 'S' is opened. |
| A. | 0 |
| B. | 2 |
| C. | 3 |
| D. | 5 |
| Answer» D. 5 | |
| 34. |
The silicon sample with unit cross-sectional area shown below is in thermal equilibrium. The following information is given: T = 300 K, electronic charge = 1.6 x 10-19C, thermal voltage = 26mV and electron mobility = 1350 cm2/V-sThe magnitude of the electric field at x = 0.5 μm is |
| A. | 1 kV/cm |
| B. | 5 kV/cm |
| C. | 10 kV/cm |
| D. | 26 kV/cm |
| Answer» D. 26 kV/cm | |
| 35. |
Two D flip-flop as shown below are to be connected as a synchronous counter that goes through the following Q1Q0 sequence00 ‚Üí 01 ‚Üí 11 ‚Üí 10 ‚Üí 00 ‚Üí __________ The inputs D0 and D1 respectively should be connected as |
| A. | Q1 and Q0 |
| B. | Q0 and Q1 |
| C. | Q1 Q0 and Q1 Q0 |
| D. | Q1 Q0 and Q1 Q0 |
| Answer» B. Q0 and Q1 | |
| 36. |
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. | |
| 37. |
Which one of the following materials is used for making permanent magnets? |
| A. | Steel |
| B. | Carbon |
| C. | Carbon-Steel |
| D. | Graphite |
| Answer» D. Graphite | |
| 38. |
Which among the following waveforms can be reconstructed from its samples without distortion? |
| A. | 1 and 2 |
| B. | 2 and 3 |
| C. | 1 and 3 |
| D. | Only 2 |
| Answer» B. 2 and 3 | |
| 39. |
Which of the following are the memory performance parameters? Access time and latencyBlock size and Block access timeCycle time and Bandwidth Select the correct answer from the codes given below: |
| A. | 1 only |
| B. | 1 and 2 only |
| C. | 2 and 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 40. |
In the silicon BJT circuit shown below, assume that the emitter area of transistor Q1 is half that of transistor Q2.The value of current I0 is approximately |
| A. | 0.5 mA |
| B. | 2 mA |
| C. | 9.3 mA |
| D. | 15 mA |
| Answer» C. 9.3 mA | |
| 41. |
Consider differential equation with the initial condition y(0) = 0. Using Euler's first order method with a step size of 0.1, the value of y(0.3) is |
| A. | 0.01 |
| B. | 0.031 |
| C. | 0.0631 |
| D. | 0.1 |
| Answer» C. 0.0631 | |
| 42. |
If the Laplace transform of the voltage transform of the voltage across a capacitor of value F is the value of the current through the capacitor at t = 0+ is |
| A. | 0 |
| B. | 0.083333333333333 |
| C. | A |
| D. | 0.041666666666667 |
| Answer» D. 0.041666666666667 | |
| 43. |
The inconsistency of Ampere's law can be removed by adding __________ to it. |
| A. | displacement current density alone. |
| B. | conduction current density alone. |
| C. | displacement and conduction current densities. |
| D. | none of these |
| Answer» B. conduction current density alone. | |
| 44. |
If g(t) = e-pt2 then G(1/p) is __________ where g(t) G(f) |
| A. | e-2/p |
| B. | e-1/p |
| C. | e-p |
| D. | e2p |
| Answer» C. e-p | |
| 45. |
For the network shown below, the Thevenin voltage and RTH is equal to __________ |
| A. | 0 V, 58.82 Ω |
| B. | 0 V, 96.774 Ω |
| C. | 0 V, 3 KΩ |
| D. | None of these |
| Answer» B. 0 V, 96.774 Œ© | |
| 46. |
A single turn loop is situated in air, with a uniform magnetic field normal to its plane. The area of the loop is 5 m2 and the rate of change of flux density is 2 Wb/m2/s. What is the emf appearing at the terminals of the loop? |
| A. | -5 V |
| B. | -2 V |
| C. | -0.4 V |
| D. | 0 V |
| Answer» B. -2 V | |
| 47. |
A speech signal, band limited to 4kHz and peak voltage varying between + 5V and - 5V is sampled at the Nyquist rate. Each sample is quantized and represented by 8 bits. The number of quantization levels required to reduce the quantization noise by a factor of 4 would be |
| A. | 1024 |
| B. | 512 |
| C. | 256 |
| D. | 64 |
| Answer» C. 256 | |
| 48. |
Consider the following statements regarding registers and latches: Registers are made of edge-triggered FFs, whereas latches are made from level-triggered FFs. Registers are temporary storage devices whereas latches are not. A latch employs cross-coupled feedback connections. A register stores a binary word whereas a latch does not. Which of the above statements is/are correct? |
| A. | 1 only |
| B. | 1 and 3 |
| C. | 2 and 3 |
| D. | 3 and 4 |
| Answer» C. 2 and 3 | |
| 49. |
An air-filled rectangular waveguide has dimensions 8cm x 10cm . The group velocity is |
| A. | 1.8 x 108 m/s |
| B. | 2.6 x 108 m/s |
| C. | 3 x 108 m/s |
| D. | 0.3 x 108 m/s |
| Answer» C. 3 x 108 m/s | |
| 50. |
Which of the following bridges is also used in an oscillator? |
| A. | Maxwell |
| B. | Schering |
| C. | Hay |
| D. | Wien |
| Answer» E. | |