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ECE :: Exam Questions Paper

  1. What are the minimum number of 2 to 1 multiplexers required to generate a 2 input AND gate a 2 input Ex-OR gate?

  2. A.
    1 and 2
    B.
    1 and 3
    C.
    1 and 1
    D.
    2 and 2

  3. Transfer function of a certain system is:

    The approximate 2% settling time for unit step input is

  4. A.
    2 sec
    B.
    4 sec
    C.
    6 sec
    D.
    8 sec

  5. On which bands, do the optical fibers operate?

    1. Ultra violet band
    2. Ultra high frequency band
    3. Visible light band
    4. Infrared band
    Select the correct answer from the codes given below:

  6. A.
    1 only
    B.
    1 and 2 only
    C.
    1, 2 and only
    D.
    1, 3 and 4

  7. A 3 stage Johnson counter shown in figure is clocked at a constant frequency of fc from the starting state of Q0 Q1 Q2 = 101. The frequency of output Q0 Q1 Q2 will be

  8. A.
    fc/2
    B.
    fc/3
    C.
    fc/6
    D.
    fc/8

  9. Which of the following conditions should be satisfied to call an astable multivibrator circuit using discrete components as a digital circuit?

    1. A flip-flop is always a digital circuit.
    2. Only when we assign 1 and 0 to the high and low levels of the output, a flip-flop is called a digital circuit.
    3. Only if the power, supply voltage is maintained at + 5 V or - 5 V, it is called a digital circuit.
    4. Only if it is in IC form, following the technology of IC manufacture, it is called a digital circuit.
    Select the correct answer from the codes given below:

  10. A.
    1 only
    B.
    2 and 3
    C.
    2 only
    D.
    3 and 4

  11. A 4 bit shift register is initialized to value 1000 for (Q3, Q2, Q1, Q0). The D input is derived from Q0, Q2 and Q3 through two XOR gates as shown in figure. The pattern 1000 will appear at

  12. A.
    3rd pulse
    B.
    7th pulse
    C.
    6th pulse
    D.
    4th pulse

  13. Assertion (A): Capacitance of a solid conducting spherical body of radius 'a' is given by 4 pε0a in free space.

    Reason (R): Δ x H = jωεE + J.

  14. 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

  15. Choose the correct statement/statements :

  16. A.
    In case of an antenna, the antenna resistance and loss resistance are not two different quantities.
    B.
    The loss resistance includes loss by eddy currents, improper earth connections, insulation leakages, etc., but not I2R losses.
    C.
    Radiation resistance varies directly as square-root of frequency
    D.
    None

  17. The PCM signal shown below uses amplitude level of +1 volt and -1 volt to represent binary symbol 0 and 1 respectively. Each code word consists of 4 bits. The sampled version of analog signal from which this PCM signal is derived is

  18. A.
    EB596
    B.
    CD231
    C.
    DA495
    D.
    25B6A

  19. Consider a situation where number of minterms with even number of 0's are same as number of minterms with odd number of 1's. Then minterms with even number of 0's and minterms with odd number of 1's are __________ to each other then number of variables is __________ .

  20. A.
    equivalent, even
    B.
    complement, odd
    C.
    complement, even
    D.
    none of these