Need help with solving currents using mesh analysis

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
1 replies · 2K views
meanmachine
Messages
3
Reaction score
0

Homework Statement


2uivnva.png


i can't write the problem text as it is a circuit


2. Homework Equations

I labelled the meshes as clockwise shown on the image
KVL: The sum of voltages around a loop equals zero

The Attempt at a Solution



i1 = 8A

i2: 19(i1 - i2) - 5.54(i2-i3) = 0

i3 = 1.7A (I created a supermesh around the 1.7A current source - inside the BLUE square)
Supermesh equation => i3 - i4 = 1.7A

i4 = 0

i5: (I used KVL around the outside of the blue square)
5.54(i2 - i3) -0.5i3 - 0.29(i4 - i5) -12.6(i4 - i5) - 0.5i3

Can some verify these equations and check they are correct?
 
on Phys.org
meanmachine said:

Homework Statement


2uivnva.png


i can't write the problem text as it is a circuit
But you can at least state what circuit values are required, right? Is it just the mesh currents? Some particular voltage drops? Maybe the power consumed by certain components? Don't leave us guessing!

2. Homework Equations

I labelled the meshes as clockwise shown on the image
KVL: The sum of voltages around a loop equals zero

The Attempt at a Solution



i1 = 8A

i2: 19(i1 - i2) - 5.54(i2-i3) = 0

Okay so far...

i3 = 1.7A (I created a supermesh around the 1.7A current source - inside the BLUE square)
Supermesh equation => i3 - i4 = 1.7A

i4 = 0
Your supermesh constraint equation is good but your "conclusion" that i3 = 1.7A is unfounded. How did you conclude that i3 = 1.7A and that i4 = 0?

i5: (I used KVL around the outside of the blue square)
5.54(i2 - i3) -0.5i3 - 0.29(i4 - i5) -12.6(i4 - i5) - 0.5i3
No, that doesn't look right; it's not even an equation (no "=" sign). Check what current is actually flowing through the 500m resistors; Looks like i4 to me. Also, what happened to the voltage source in the the supermesh loop? Also, you need to write a separate equation for the i5 loop; Two voltages sources there!