Module 2.3 Series-Parallel Circuits & Conductance PDF

Preview

Summary

Detailed course notes that includes formulas and tutorial work related to the topic....

Description

CONDUCTANCE Conductance is the reciprocal of resistance and is an indication of the ease with which a circuit will permit current to flow. Symbol - G

Unit - Sieman (S)

For the parallel circuit: 1

1

=

RT

R1

+

1

+

R2

1

+ .......

R3

Written in terms of conductance

GT = G1 + G2 + G3 + ...... This shows that conductances in parallel add directly.

Ohm's law may also be written in terms of conductance. I=

E

=Ex

RT

Example

1 RT

= E xGT

Solve previous problem using conductances. Converting the resistances to conductances.

SERIES-PARALLEL CIRCUITS A circuit containing both series and parallel branches is designated a series-parallel or combination circuit. To find the total resistance of such a circuit, it is necessary to reduce the circuit systematically by combining the series and parallel sub-circuits. Example

For the circuit shown below calculate: (a) Total resistance (b) Current in the 4 resistor

(a) 1st step is to combine the parallel combination of 4 and 12 .

The circuit can now be reduced to:

Applying the series circuit rule:

(b) By current division:

or

Find voltage across the 3 equivalent resistance:

Example

In the following circuit calculate: (a) IT (b) I4 (c) V9...