Chapter 8 – Methods of Analysis

Lecture 9A - Tutorial

by Moeen Ghiyas

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Branch Current Analysis

Mesh Analysis Method (General Approach)

Super Mesh Currents

# 16 – For the transistor configuration of Fig:

a) Solve for the currents IB, IC, and IE using the fact that VBE = 0.7 V and

VCE = 8 V.

b) Find the voltages VB, VC, and VE with respect to ground.

c) What is the ratio of output current IC to input current IB? [Note: In

transistor analysis this ratio is referred to as the dc beta of the

transistor (βdc)].

a) Solve for the currents IB, IC, and IE using the fact that VBE = 0.7 V and

VCE = 8 V.

Solution:

o KVL in loop 1

o KVL in loop 2

o KCL at 1 node

o Solving simultaneously

b) Find the voltages VB, VC, and VE with respect to ground.

Solution : Using basic tools of electrical engineering....

c) What is the ratio of output current IC to input current IB? [Note: In

transistor analysis this ratio is referred to as the dc beta of the

transistor (βdc)].

# 24 – Using mesh analysis, determine the current through

the 5Ω resistor for network of fig. Then determine voltage Va.

Solving we get

Now for Va

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# 24 – Find the current through each element of the networks of fig.

Decide which approach would you use and why?

Mesh - general approach gets I4Ω wrong, so we choose super-mesh

Solution:

# 24 – Find the current through each element of the networks of fig.

Solution: For super-mesh we open circuit current source

Super-mesh loop:

KCL for co-relation eq.

# 24 – Find the current through each element of the networks of fig.

Simultaneous solving &

Determinants – (Appendix C of Book)

Mesh Analysis Method (General Approach)

Super Mesh Currents

Mesh Analysis Method (Format Approach)

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Consider the following equations, where x and y are the

unknown variables and a1, a2, b1, b2, c1, and c2 are constants:

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Example: Solve for x and y.

Solution:

Check your answer by putting the calculated values in original

equation and see if it tallies 14/05/23 14

Consider the three following simultaneous equations in which

x, y, and z are the variables, and a1,2,3, b1,2,3, c1,2,3, and d1,2,3 are

constants:

where

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Sign of each cofactor

we can find the minors of a1 and b1 as follows:

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