solving ohms law

Discussion in 'Homework Help' started by purecilia, Dec 29, 2008.

  1. purecilia

    Thread Starter Member

    Dec 29, 2008
    12
    0
    hello !!!

    I am still new to this forum.i have encountered an ohms law question can anyone tell me how shall i work this question it might be really easy for you but for me its a bit complicated considering that i have just started studying electronics..... check this out !!!
     
  2. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    First find the equivalent resistance of the two 10 ohm parallel resistors which is 5ohms. Then add it with the two other 10 ohm resistors which are in series with it to get 25 ohms. The current is 2A and thus the voltage is 2*25=50V
     
  3. purecilia

    Thread Starter Member

    Dec 29, 2008
    12
    0
    hi !!
    Thanks but now I need to find
    1)The voltage across the parallel resistors
    2)the power dissipated in resistor A if the value of each resistor was doubled ??
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    What values have you been able to calculate?
     
  5. purecilia

    Thread Starter Member

    Dec 29, 2008
    12
    0
    I was able to find the voltage across the whole circuit but the question is that I have to find the voltage across the parallel resistors only and I found total resistance, I have to find .....

    1)The voltage across the parallel resistors
    2)The power disspated in resistor A if the value of each resistor was doubled
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    Given the total current of 2 amps, what voltage is across each of the resistors?

    Hint: E = IR
     
  7. purecilia

    Thread Starter Member

    Dec 29, 2008
    12
    0
    hello !!
    I'll give it atry someone confirm it please ...
    V=IR
    V=2*5
    V=10V
    But I still have question 2 please someone help me
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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  9. purecilia

    Thread Starter Member

    Dec 29, 2008
    12
    0
    hi !!!

    I am still confused the current is 4 amps than
    V=IR
    V=4*5
    V=20v

    someone confirm it please !!

    Thanks
     
  10. vvkannan

    Active Member

    Aug 9, 2008
    138
    11
    Hello purecilia,
    If the value of resistors are doubled then the current would reduce by half as the voltage is constant.
    And then calculate the power using any of the formulae given here
    http://www.allaboutcircuits.com/vol_1/chpt_2/4.html.
    Hope this answers your second question.
     
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