Anonymous
Anonymous asked in Science & MathematicsPhysics · 1 month ago

Can someone solve these?

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  • 1 month ago
    Favorite Answer

    a and b are the same with different values. c requires a Y to delta transformation

    b) 300 and 150 in series = 450

    60 and 90 in series = 150

    now you have 450 and 150 in parallel which is

    450•150/600 = 112.5 Ω

    that is in series with 20 for a total R of 132.5 Ω

    battery current = 8/132.5 = 0.0604 amps

    voltage across the parallel pair = .0604 x 112.5  = 6.79 volts

    that causes current in both the 300 and 150 of

    6.79 / 450 = 0.0151 amps

    and it causes current in both the 90 and 90 of6.79 / 150 = 0.0453 amps

    and they add up to 0.0604 amps as a check

    power in the 150 = I²R = 0.0151²150 = 0.0342 watts

    the second I'll leave to another answer.

    hint: apply a Y to delta transformation to the 4,5,6 Ω resistors, then you have simple parallel series combos.

  • garry
    Lv 5
    1 month ago

    how about reading your electrical chart and work it out yourself , its under ohms law , basic eletrical formula ..

  • 1 month ago

    Assume i1, i2 an i3 clockwise currents in the left, bottom and top loops. Currents I1, I2, I3, I4 and I5 will be found using those.

    The equations are:

    -5i1 + 3i2 + 2i3 = -6.6

    +3i1 -  12i2 + 5i3 = 0

    +2i1 + 5i2 - 13i3 = 0

    With the equations you can use any method for simultaneous solutions. 

    Multiply 3rd eq. by -1.5 and add to 2nd eq,

    -39i2 + 49i3 = 0 so i3 = 39i2/49

    Multiply the 2nd eq by 5/3 and add to 1st eq.

    -17i2 + 31i3/3 = -6.6

    i3 = 51i2/31 - 19.8/31 = 39i2/49

    i2(51/31 - 39/49) = 19.8/31

    i2 = 0.7521

    i3 = 0.5986

    i1= (3*0.7521+2*0.5986+6.6)/5 = 2.01

    I1 = 2.01 - 0.7521 = 1.259

    I2 = 0.7521

    I3 = i2 - i3 = 0.1535  

    I4 = I3 + I1 = 1.412

    I5 = 2.01 - 1.412 = 0.599

     

  • oubaas
    Lv 7
    1 month ago

    fig. (a)

    Req = (16 // 6) + 3 = 96/22 + 3 = 162/22 = 81/11 ohm

    I = V/Req = 20*11/81 =  220/81 = 2.716 A 

    fig. (b)

    Req = (150 // 450) + 20 = 50*(27/12) + 20 = (1350+240)/12 = 1590/12 ohm

    I = V/Req = 8*12/1590 = 96/1590  A 

    I(300) = I*150/600 = 24/1590 A 

    I(90) = I*450/600 = 72/1590 A

    P(150) = 150*24^2/1590^2 =  34.2 mwatt

     

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  • david
    Lv 7
    1 month ago

    electric resistance / current problems - - - this is PHYSICS

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