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Electronics true or false questions

  1. Nov 13, 2011 #1

    Femme_physics

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    Can you help confirm whether my answers are correct or not?


    ------------------------------

    True or False (+answer must be explained)

    Question #1:

    Ripple is an alternative component of the DC component of an electrical signal

    Answer #1: True. A period, accoriding to wiki, is "small unwanted residual periodic variation of the direct current (dc) output of a power supply which has been derived from an alternating current (ac) source."

    Question #2:

    The saturation current in a transistor is greater than the conductance current

    Answer #2: Not true.

    Saturation current = 0
    So it can't be greater than the conductance current!
    The conductance current is greater than the saturation current.

    Question #3: The following amplification of the op-amp is

    Af = 1 + R1/R2

    http://img833.imageshack.us/img833/3954/noninvert.jpg [Broken]



    Answer #3: True.

    Since what we have here is a non-inverting op-amp, that's its formula.

    Question #4: The duty cycle of the repeating signal is 40%
    http://img15.imageshack.us/img15/3328/dutyc.jpg [Broken]



    Answer #4: Not true. Duty cycle is measured when there is current, not when there isn't. Therefor, in this case, it's 60%.

    6/10 x 100 = 60%
     
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Nov 13, 2011 #2

    I like Serena

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    I'll give it a try! :smile:
    Hope it helps.


    Good!


    I do not know what you mean by "conduction current"... :confused:
    There's a couple of possibilities.

    But saturation current is when the transistor is saturated with so much base current that it can't open any wider.
    This is the highest current you can get...


    It is *almost* the formula...
    Can you spot the difference?



    Yep! :smile:
     
    Last edited by a moderator: May 5, 2017
  4. Nov 13, 2011 #3

    Femme_physics

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    You, always.

    Oh, so my bad. Yes, I forgot...it's kinda in the word, "saturated". *smacks forehead*

    So, saturated must always be the highest current, therefor it must be higher than the "conductance current" (It's just the direct translation from hebrew)


    EDIT: The translation may be "threshold current", am not sure.

    Yes, R1 an R2 are opposite in this case. Got it. Thanks! :smile:



    Glad I got the other 2 right!
     
    Last edited: Nov 13, 2011
  5. Nov 13, 2011 #4

    I like Serena

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    So it's all good now! ;)

    Threshold current sounds a bit like cutoff current.
    Remember that that was the opposite from saturation?

    From wikipedia:
     
  6. Nov 14, 2011 #5

    Femme_physics

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    Thanks, ILS. my savior.. :smile:
     
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