not sure about Vrms (my exam question)

Discussion in 'Homework Help' started by STUDENT_LV, Aug 13, 2007.


    Thread Starter New Member

    Aug 13, 2007
    a cirucit in full wave rectifier.

    from the V primary , they give Vac suppy 110v. nisbah 2:1

    Vsec = i use the vac suppy to 110/0.707 then use the nisbah to find the vsec ritE? Vrms for my sch = 0.707 i wan to know is i need to use Vrms or not ? get wat i mean ? my english very poor >< must reply me pls. important for the mark
  2. recca02

    Senior Member

    Apr 2, 2007
    u shud be studying the topic,
    if u cant answer that it means u shud study harder,
    one question
    do u know the turns ratio
  3. amit_eie

    New Member

    Aug 15, 2007
    Vrms means Root Mean square value.
    Vrms=0.707Vm,I suppoese Vm =110,then calculate result.plz put your question in more details so that i can help you.
  4. RiJoRI

    Well-Known Member

    Aug 15, 2007
    Comment: if someone states his or her English is very poor, using abbr.s lk shud dsnt help 'em A-TALL! ;)

    Student_LV: the English word for "nisbah" is "ratio." Mains voltages are given in RMS, unless otherwise stated. So, given an input of 110Vrms, with a ratio of 2:1, the transformer's output would be 55Vrms.

    Also see for more about rectification.

    I trust this helps!
  5. techroomt

    Senior Member

    May 19, 2004
    please don't come in a' blastin', i'm sure there was no intent there.

    any voltage value (p-p, peak, avg, rms)can be applied to the transformer turns ratio, you just need to be consistent using the same for "in" as you do for "out".
  6. recca02

    Senior Member

    Apr 2, 2007
    oh i m sorry, i will take that into consideration next time its just a bad habit i shud improve on :)
    and yup as MR techroomt said any value can be used in eqn the answer will be in that form (need we even mention that?)

    Student_LV: it is also true that voltages are generally specified in terms of Vrms (as stated) unless stated otherwise however for academics always state your assumptions in the answer.