Home / ECE / Network Analysis and Synthesis :: Section 9

ECE :: Network Analysis and Synthesis

  1. If P = 250 W and p.f. = 0.707 lagging, Q =

  2. A.
    250 vars
    B.
    - 250 vars
    C.
    176.7 vars
    D.
    - 176.75 vars

  3. Assertion (A): Energy stored in inductance is and that in capacitance is

    Reason (R): Inductance and capacitance are dual of each other.

  4. A.
    Both A and R are true and R is correct explanation of A
    B.
    Both A and R are true and R is not the correct explanation of A
    C.
    A is true but R is false
    D.
    A is false but R is true

  5. The time constant of the circuit after the switch shown in the figure is opened is

  6. A.
    0.2 s
    B.
    5 s
    C.
    0.1 s
    D.
    dependent on R and hence cannot be determined unless R is known

  7. A series RLC circuit is at resonance at 200 Hz. If capacitance is increased to four times, the circuit will be in resonance at

  8. A.
    200 Hz
    B.
    400 Hz
    C.
    100 Hz
    D.
    800 Hz

  9. A system function the resonant frequency in rad/sec and bandwidth in rad/sec. is given by

  10. A.
    10 and 1
    B.
    10, 4
    C.
    100, 5
    D.
    10, 10

  11. The temperature coefficient of copper is 0.00393 at 20° C. At 50° C the temperature coefficient is

  12. A.
    0.0042
    B.
    0.0035
    C.
    0.0025
    D.
    0.0015

  13. To determine the polarity of voltage drop across a resistor, it is sufficient to know

  14. A.
    direction of current through the resistor
    B.
    direction and magnitude of current through the resistor
    C.
    direction and magnitude of current and value of resistance
    D.
    magnitude of current through the resistance

  15. A sawtooth current wave is passed through a resistance

  16. A.
    the waveshapes of voltages across resistance and power will also the sawtooth
    B.
    the waveshape of voltage across resistance will be sawtooth
    C.
    the waveshape of power will be sawtooth
    D.
    neither the voltage waveshape nor power wave-shape will be sawtooth

  17. Which of the following is the poorest conductor of electricity?

  18. A.
    Copper
    B.
    Aluminium
    C.
    Manganin
    D.
    Nichrome

  19. Assertion (A): If A = 0.5 ∠ 20°, A2 = 0.25 ∠ 40°.

    Reason (R): When drawing a phasor diagram, sinusoids may have the same or different frequencies.

  20. A.
    Both A and R are true and R is correct explanation of A
    B.
    Both A and R are true and R is not the correct explanation of A
    C.
    A is true but R is false
    D.
    A is false but R is true