Mesh Analysis

1
Mesh Analysis

• Examples

2
Example 1
3
Using Mathcad
4
Using PSpice
I1 -1818 A
I2 -6.364 A
5
Example 2 By Inspection
6
Using Mathcad By Inspection
7
Using PSpice
8
Example 3
9
Using Mathcad
Mesh 1
10
Using PSpice
I1 250 mA
11
Example 4 Supermesh
Mesh 1 and mesh 2 form supermesh
I2 4.4 A
I1 -1.6 A
Ans
12
Using Mathcad
13
Using PSpice
I1 -1.6 A
I2 4.4 A
Ans
14
Example 5 Supermesh
15
Example 5 Supermesh
I3 -1.81A
I2 -3.621A
I1 5.431A
Ans
16
Using Mathcad equations
17
Using Mathcad Results
18
Using PSpice
I3 -1.81A
I2 -3.621A
I1 5.431A
Ans
19
Problem 1
Find Va and Ix
20
Using Mathcad
21
To Find Ix
Ix -I1 -3.474 A
22
To Find Va

V2
V4
-
-



V1
-
V8
-
Mesh 1 -6(I1-I3)?2(1 ? 3)Va 0
Mesh 2 -(1 ? 3) (I2-I3)48I2-Va 0
or
Va -1.737V
23
Problem 2
2Ia
10
-

I3
Ia
x
y
40
8
Ib
-
5A
I2
80
I1
Vc
20V
5A
2.5Ib

Find Vxy, Vc, and the power absorbed by all
elements.
24
Using Mathcad Equations
25
Using Mathcad Results
26
To Find Vxy
2Ia
10
-

I3
Vxy
x
y

-
Ib
-
5A
I2
80
I1
Vc
20V
5A
2.5Ib

-Vxy-2Ia10I3 0
Vxy, Vc
Vxy -2Ia10I3
27
To Find Vc
2Ia
10
-

I3
x
y
40

-
V40
Ib
-
5A
I2
80
I1
Vc
20V
5A
2.5Ib

Vc(I2-I3)40-20 0
Vc -(I2-I3)4020
28
Power absorbed by active elements
2Ia
10
-

I3
Ia
x
y
40
8
-
Ib
-
5A
V5A
I2
80
I1
Vc
20V
5A

2.5Ib

For the active elements, we have to follow PSC to
calculate the power absorbed.
29
Power absorbed by passive elements
2Ia
-

I3
10
Ia
x
40
8
-
Ib
-
5A
V5A
I2
80
I1
Vc
20V
5A

2.5Ib

The power absorbed by the resistor is always
positive we can always use P I2R
30
Power absorbed by all elements