Voltage and Current

Discussion in 'General Electronics Chat' started by circ, Feb 18, 2010.

  1. circ

    Thread Starter New Member

    Feb 18, 2010
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    0
    Hey Guys

    I am new to electronics and currently on the ohms law chapter on vol 1. I have a question about voltage and current, I read it somewhere in one of the chapters but I cannot find it. Is current always consistant throughout a circut whereas voltage will vary from one part of the circut to the other ?

    EDIT: Here are some other questions I am also puzzled about:

    What exactly is a voltage drop ?
    How do resistors work ? I know the type of material, its cross-section etc play a role. But is it because the electrons in resistors have a 'stronger' attractions to the protons hence more 'friction' = heat dissipation ?
     
    Last edited: Feb 18, 2010
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    For a simple single loop circuit, your statement is basically true. For more complex multiloop circuits the total current in the circuit is distributed on the basis of the resistances and voltage and/or current sources that make up the circuit.

    Do you have a specific circuit in mind?

    hgmjr
     
  3. circ

    Thread Starter New Member

    Feb 18, 2010
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    0
    Thanks. No circut in particular, just attempting to understand the concept.
    I have a Q about resistors: When a resistor is inserted into a circut, does the current decrease ?
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    Yes. The current decreases when a resistor is placed in a circuit. (unless it is a 0 ohm resistor, sometimes used as a jumper)
     
  5. circ

    Thread Starter New Member

    Feb 18, 2010
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    Ok, does it decrease the current once the resistor is done with it or does it reduce the current in the 'whole' circut (assuming its a simple circut with a battery and resistor).
     
  6. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    After it. It also depends on how the components before the resistors are loaded. If you have a high draw component and a low draw component in the same circuit, you would need a resistor to after the high draw to keep the low draw from burning up.
     
  7. circ

    Thread Starter New Member

    Feb 18, 2010
    10
    0
    Thanks. Another question. Im on the chapter about electric safetly. The author went into grounding a circut and its importance. Now, if a person touches a part of the wire which is 'electrically common' then he will not be shocked, but if he touches another part of the wire which isnt common then he will be shock. Illustration below:

    [​IMG]

    My question is how comes electrically common connections dont invoke a shock whereas non-electrically common connections do ? Is it to do with the variation in voltage ?








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