Write a complete set of mesh equations for the circuit.

NOTE to Grader: The students only had to write the equations. They did not have to simplify or solve them.

VD = 5 (I₂ - I₁)

Next, relate the value of the dependent current source to the mesh currents.

0.2 VD = I₃

Combining these two equations to eliminate the extra variable () yields:

I₂ - I₁ = I₃

or

- I₁ + I₂ - I₃ = 0 (Eq. 1)

Removing the dependent current source leaves only two meshes, 1 and 2.

KVL around mesh 1.

17.5 I₁ + 2.5 I₁ - 2.5 I₃ + 5 I₁ - 5 I₂ = 0

25 I₁ - 5 I₂ - 2.5 I₃ = 0 (Eq. 2)

KVL around mesh 2.

5 I₂ - 5 I₁ + 7.5 I₂ - 7.5 I₃ + 50 - 125 = 0

- 5 I₁ + 12.5 I₂ - 7.5 I₃ = 75 (Eq. 3)

I₁ = 3.6 A

I₂ = 13.2 A

I₃ = 9.6 A