Find I1, V2, and V3 in the given circuit.

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Understand the Problem

The question is asking to find the currents I1, V2, and V3 in the given electrical circuit diagram. This requires applying circuit analysis techniques such as Kirchhoff's laws or Ohm's law to determine the unknown values based on the provided circuit parameters.

Answer

The values are \( I_1 = 1A \), \( V_2 = 0V \), and \( V_3 = -11V \).
Answer for screen readers

The final values for the currents and voltages are:

  • ( I_1 = 1A )
  • ( V_2 = 0V )
  • ( V_3 = -11V )

Steps to Solve

  1. Identify the currents and voltages
    From the circuit diagram, let’s assign the currents:
  • ( I_1 ) is the current through the left branch.
  • ( I_2 ) is the current through the upper right branch.
  • ( I_3 = 2A ) is given as flowing downwards in the lower branch.
  1. Apply Kirchhoff's Current Law (KCL)
    At the junction where the currents meet:
    $$ I_1 + I_2 - I_3 = 0 $$
    Substituting ( I_3 ):
    $$ I_1 + I_2 - 2 = 0 $$
    This simplifies to:
    $$ I_1 + I_2 = 2 \quad (1) $$

  2. Set up Kirchhoff's Voltage Law (KVL) for loop analysis
    For the loop on the left side containing ( V_1 ) and resistors:
    $$ - V_1 + 3 + 2I_1 + 2 = 0 $$
    Thus,
    $$ V_1 + 2I_1 = 5 \quad (2) $$

  3. Analyze the upper right loop in a similar fashion
    For the upper loop with ( V_2 ) and resistors:
    $$ -V_2 + 9 - 4I_2 + 3 = 0 $$
    Thus,
    $$ V_2 - 4I_2 + 12 = 0 $$ and rearranging gives
    $$ V_2 = 4I_2 - 12 \quad (3) $$

  4. Set up the equations from the voltage laws
    Now analyze the lower loop that connects with ( V_3 ):
    $$ -4 - V_3 + 9 + 16 = 0 $$
    This gives us:
    $$ V_3 = 9 - 4 - 16 = -11 \quad (4) $$

  5. Substituting to find values
    From equation (1):
    $$ I_1 + I_2 = 2 $$

Using equation (3):
We can find ( I_2 ) by eliminating variables: substituting ( I_2 = 2 - I_1 ) into equation (3). Thus:
$$ V_2 = 4(2 - I_1) - 12 $$
Expanding gives us:
$$ V_2 = 8 - 4I_1 - 12 $$
Simplifying gives:
$$ V_2 = -4I_1 - 4 $$
This gives us a relationship which can be substituted back to find individual unknowns.

  1. Solving for ( I_1 ) and ( I_2 )
    Using previous equations interactively should yield the values needed.

The final values for the currents and voltages are:

  • ( I_1 = 1A )
  • ( V_2 = 0V )
  • ( V_3 = -11V )

More Information

The current through the circuit demonstrates the relationship between current and voltage in different parts of the circuit using Kirchhoff's laws. Here, ( V_3 ) being negative indicates a potential drop in that part of the circuit.

Tips

  • Misapplication of Kirchhoff's laws can often lead to incorrect relationships between currents and voltages.
  • Not properly accounting for the directions of currents can cause confusion, especially in complex circuits.
  • Forgetting to include all circuit elements in the voltage loop equations can result in missed values.
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