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Two D.C. shunt generators, each with armature resistance of 0.02 ohm and field resistance of 50 ohm run in parallel and supply a total current of 1000 amperes to the load circuit. If their e.m.fs. are 270 V and 265 V, their bus bar voltage will be

A. 270 V

B. 267.5 V

C. 265 V

D. 257.4 V

Answer: Option B


This Question Belongs to Electrical Engineering >> D.C. Generators

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Comments ( 12 )

  1. Golam Rabbi
    Golam Rabbi :
    1 month ago

    The right ans is 257.5v

  2. Kalyani Dhawad
    Kalyani Dhawad :
    5 months ago

    Bus Bar Voltage=
    ∑(Individual Field Resistances)
    ∑(Individual E.M.F.s×Individual Field Resistances)+Total Load Current×Total Armature Resistance



    Let's calculate:

    Bus Bar Voltage
    =
    (
    270
    ×
    50
    )
    +
    (
    265
    ×
    50
    )
    +
    (
    1000
    ×
    0.02
    )
    50
    +
    50
    Bus Bar Voltage=
    50+50
    (270×50)+(265×50)+(1000×0.02)



    Bus Bar Voltage
    =
    13500
    +
    13250
    +
    20
    100
    Bus Bar Voltage=
    100
    13500+13250+20



    Bus Bar Voltage
    =
    26770
    100
    Bus Bar Voltage=
    100
    26770



    Bus Bar Voltage
    =
    267.7

    V
    Bus Bar Voltage=267.7V

  3. Vishal Sawant
    Vishal Sawant :
    5 months ago

    I1+I2=1000A
    I1=Eg1-v/Ra
    I2=Eg2-v/Ra
    I1+I2=270-v/Ra+265-v/Ra
    Solve it than we find
    2v=535
    V=535/2
    V =267.5v

  4. Mujibul Haque
    Mujibul Haque :
    3 years ago

    D is the correct answer

  5. Routhu Saivamsi
    Routhu Saivamsi :
    3 years ago

    I1+I2=1000A

    I1=Eg1-V/Ra

    I2= Eg2-V/Ra

    I1+I2= 270-V/Ra +265-V/Ra

    Solve it than we find

    2V=515

    v= 257.5

  6. Rock Gaming
    Rock Gaming :
    3 years ago

    In DC generators brushes are used for

  7. Srinu Kumar
    Srinu Kumar :
    3 years ago

    Solve the problem

  8. Sandhya Mohite
    Sandhya Mohite :
    3 years ago

    Please solve this problem

  9. Rajeev Kumar
    Rajeev Kumar :
    4 years ago

    The given answer is wrong.The full solution is little bit lengthy,so we should try it using options.Since armature resistance is identical in both generators,the generator with high emf should supply more current (i.e. more than 500A)to the load.So the drop on the armature resistance should be more than 500A *0.02 =10v.So the terminal voltage must be less than 270-10=260V.By looking at the option the only possible answer is D.

  10. Abdallah Hussein
    Abdallah Hussein :
    4 years ago

    the avareage

  11. Rohit Kumar
    Rohit Kumar :
    5 years ago

    Please solve this problem

  12. Priyanka Raj
    Priyanka Raj :
    5 years ago

    Please solve this problem

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