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Arranging resistors to have a minimum equivalent

  1. Jun 11, 2017 #1
    1. The problem statement, all variables and given/known data

    The minimum resistance obtained by connecting 50 resistances of 0.25 ohm each is
    A)50/4ohm B)4/50 ohm C)200 ohm D)1/200 ohm
    2.Relevant equations
    1.When resistances are connected in series,
    ▪R(equivalent)=summation of all individual resistances
    2.When resistances are connected in parallel ,
    ▪1/(equivalent resistance) =1/(summation of reciprocals of individual resistances)
    3. The attempt at a solution
    Minimum resistance is usually obtained when all resistances are connected in parallel (better than adding them all up).
    So,it should be coming as 4/50 ohms,using formula 2,but the answer is given as D,1/200 ohms.

    How do you arrange these resistors to have an equivalent resistance of 1/200 ohms??
     
  2. jcsd
  3. Jun 11, 2017 #2

    lewando

    User Avatar
    Gold Member

    You have made a simple math error. Slow down and do it again. Show more intermediate steps if you want to know exactly which step is in error.
    You were correct when you said they should all be in parallel.
     
  4. Jun 11, 2017 #3
    I got D as well. Check your calculations.
     
  5. Jun 11, 2017 #4
    Yeah,got it,dumb me.Thanks,guys..
     
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