Chapter 6 : Series-Parallel Crcuits

Example No. 6_1 Page No. 194

In [4]:
# The Current in M1 reads 0 A with the standard resistor RS adjusted to 5642 Ohms. What is the value of the unknown resistor Rx?

# Given data

Rs = 5642.#          # Standard Resistor=5642 Ohms
R1 = 1.*10**3#        # Resistor 1=1k Ohms
R2 = 10.*10**3#       # Resistor 2=10k Ohms

Rx = Rs*(R1/R2)#
print 'The Unknown Resistance Rx = %0.2f ohms'%Rx

The Unknown Resistance Rx = 564.20 ohms

Example No. 6_2 Page No. 195

In [6]:
# what is the maximum unknown resistance Rx that can be measured for the ratio arm values shown?

# Given data

Rsmax = 9999.#      # Standard Resistor(max)=9999 Ohms
R1 = 1.*10**3#       # Resistor 1=1k Ohms
R2 = 10.*10**3#       # Resistor 2=10k Ohms

Rxmax = Rsmax*(R1/R2)#
print 'The Unknown Resistance Rx(max) = %0.2f Ohms'%Rxmax

The Unknown Resistance Rx(max) = 999.90 Ohms

Example No. 6_3 Page No. 197

In [11]:
# Assume that the series-parallel circuit in Fig. 6–15a has failed. A technician troubleshooting the circuit has measured the following voltages: V1 = 10.8 V# VAB = 9 V# V4 = 16.2 V. These voltage readings are shown in Fig. 6–15b. Based on the voltmeter readings shown, which component is defective and what type of defect does it have?

# Given data

V1 = 10.8#      # Voltage at R1=10.8 Volts
Vab = 9.0#        # Voltage at point (AB)=9 Volts
V4 = 16.2#      # Voltage at R4=16.2 Volts
R1 = 120.0#       # Resistor 1=120 Ohms


It = V1/R1#
Rab = Vab/It#
print 'The Resistance R(AB) = %0.2f ohms'%Rab

The Resistance R(AB) = 100.00 ohms