Fundamentals of Electric Circuits
6th Edition
ISBN: 9780078028229
Author: Charles K Alexander, Matthew Sadiku
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 12, Problem 35P
Three equal impedances, 60 + j30 Ω each, are delta-connected to a 230-V rms, three-phase circuit. Another three equal impedances, 40 + j10 Ω each, are wye-connected across the same circuit at the same points. Determine:
- (a) the line current
- (b) the total complex power supplied to the two loads
- (c) the power factor of the two loads combined
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
Three-phase
supply from
utility
The diagram shown in figure has two three-
phase loads that form part of a manufacturing plant. They are
connected in parallel and require 4.16 kV rms. Load 1 is 1.5
MVA, 0.75 lag pf A connected. Load 2 is 2 MW, 0.8 lagging
pf, Y connected. The feeder from the power utility's substation
transformer has an impedance of 0.4+j0.8 2/phase. Deter-
mine the following:
(a) The required magnitude of the line voltage at the supply.
(b) The real power drawn from the supply.
(c) The percentage of the real power drawn from the supply that
is consumed by the loads.
0.4 Ω j 0.8 Ω
0.4 Ω j 0.8 Ω
0.4 Ω j 0.8 Ω
m
Load 1
am
Load 2
Two delta connected loads are connected in parallel and powered by a balanced Y-connectedsource. The smaller of two loads draws 10 kVA at a lagging power factor of 0.75 and the largerdraws 25 kVA at a leading power factor of 0.8. The line voltage is 400 V. Calculate a) The powerfactor at which the source is operating. b) The total power drawn by the two loads. c) The phasecurrent of each load.
Three identical loads with complex impedance are connected to a 3-phase network 230V/400V,50Hz.
1- The three loads are coupled in delta shape (triangle). The power is measured using the two
watmeters method with W1=2740 W aand W2=980 W
A- Calculate the total active and reactive power.
B- Calculate the rms value of the line current
C- Find the magnitude of the complex impedance Z.
2- The three louds are now connected in star shape.
A- Using the value of Z found in 1)c, calculate the rms value of the line current I.
b- Calculate the total active power and reactive power
Chapter 12 Solutions
Fundamentals of Electric Circuits
Ch. 12.2 - Given that Vbn=22030V, find Van and Vcn, assuming...Ch. 12.3 - A Y-connected balanced three-phase generator with...Ch. 12.4 - One line voltage of a balanced Y-connected source...Ch. 12.5 - A positive-sequence, balanced -connected source...Ch. 12.6 - In a balanced -Y circuit, Vab=44015 and ZY = (12 +...Ch. 12.7 - For the Y-Y circuit in Practice Prob. 12.2,...Ch. 12.7 - Calculate the line current required for a 30-kW...Ch. 12.7 - Assume that the two balanced loads in Fig....Ch. 12.8 - The unbalanced -load of Fig. 12.24 is supplied by...Ch. 12.8 - Find the line currents in the unbalanced...
Ch. 12.9 - Prob. 11PPCh. 12.9 - For the unbalanced circuit in Fig. 12.32, use...Ch. 12.10 - Repeat Example 12.13 for the network in Fig. 12.24...Ch. 12.10 - Let the line voltage VL = 208 V and the wattmeter...Ch. 12.10 - If the load in Fig. 12.35 is delta-connected with...Ch. 12 - What is the phase sequence of a three-phase motor...Ch. 12 - If in an acb phase sequence, , then Vcn is:Ch. 12 - Which of these is not a required condition for a...Ch. 12 - Prob. 4RQCh. 12 - Prob. 5RQCh. 12 - In a Y-Y system, a line voltage of 220 V produces...Ch. 12 - In a - system, a phase voltage of 100 V produces a...Ch. 12 - When a Y-connected load is supplied by voltages in...Ch. 12 - Prob. 9RQCh. 12 - Prob. 10RQCh. 12 - If Vab = 400 V in a balanced Y-connected...Ch. 12 - What is the phase sequence of a balanced...Ch. 12 - Given a balanced Y-connected three-phase generator...Ch. 12 - A three-phase system with abc sequence and VL =...Ch. 12 - For a Y-connected load, the time-domain...Ch. 12 - Using Fig. 12.41, design a problem to help other...Ch. 12 - Obtain the line currents in the three-phase...Ch. 12 - In a balanced three-phase Y-Y system, the source...Ch. 12 - A balanced Y-Y four-wire system has phase voltages...Ch. 12 - For the circuit in Fig. 12.43, determine the...Ch. 12 - In the Y- system shown in Fig. 12.44, the source...Ch. 12 - Using Fig. 12.45, design a problem to help other...Ch. 12 - In the balanced three-phase Y- system in Fig....Ch. 12 - Obtain the line currents in the three-phase...Ch. 12 - The circuit in Fig. 12.48 is excited by a balanced...Ch. 12 - A balanced delta-connected load has a phase...Ch. 12 - A positive sequence wye-connected source where ,...Ch. 12 - If Van = 22060 V in the network of Fig. 12.49,...Ch. 12 - For the - circuit of Fig. 12.50, calculate the...Ch. 12 - Prob. 20PCh. 12 - Three 440-V generators form a delta-connected...Ch. 12 - Find the line currents IaA, IbB, and IcC in the...Ch. 12 - A balanced delta connected source is connected to...Ch. 12 - A balanced delta-connected source has phase...Ch. 12 - In the circuit of Fig. 12.54, if , , , find the...Ch. 12 - Using Fig. 12.55, design a problem to help other...Ch. 12 - A -connected source supplies power to a...Ch. 12 - The line-to-line voltages in a Y-load have a...Ch. 12 - A balanced three-phase Y- system has V rms and Z =...Ch. 12 - In Fig. 12.56, the rms value of the line voltage...Ch. 12 - A balanced delta-connected load is supplied by a...Ch. 12 - Design a problem to help other students better...Ch. 12 - A three-phase source delivers 4.8 kVA to a...Ch. 12 - A balanced wye-connected load with a phase...Ch. 12 - Three equal impedances, 60 + j30 each, are...Ch. 12 - A 4200-V, three-phase transmission line has an...Ch. 12 - The total power measured in a three-phase system...Ch. 12 - Given the circuit in Fig. 12.57 below, find the...Ch. 12 - Find the real power absorbed by the load in Fig....Ch. 12 - For the three-phase circuit in Fig. 12.59, find...Ch. 12 - A balanced delta-connected load draws 5 kW at a...Ch. 12 - A balanced three-phase generator delivers 7.2 kW...Ch. 12 - Refer to Fig. 12.48. Obtain the complex power...Ch. 12 - A three-phase line has an impedance of 1 + j3 per...Ch. 12 - A balanced wye-connected load is connected to the...Ch. 12 - A three-phase load consists of three 100-...Ch. 12 - The following three parallel-connected three-phase...Ch. 12 - A balanced, positive-sequence wye-connected source...Ch. 12 - Each phase load consists of a 20- resistor and a...Ch. 12 - A balanced three-phase source with VL = 240 V rms...Ch. 12 - Consider the wye-delta system shown in Fig. 12.60....Ch. 12 - A four-wire wye-wye circuit has...Ch. 12 - Using Fig. 12.61, design a problem that will help...Ch. 12 - A balanced three-phase Y-source with VP = 880 V...Ch. 12 - A three-phase supply, with the line-to-line...Ch. 12 - Using Fig. 12.63, design a problem to help other...Ch. 12 - Determine the line currents for the three-phase...Ch. 12 - Solve Prob. 12.10 using PSpice or MultiSim. For...Ch. 12 - The source in Fig. 12.65 is balanced and exhibits...Ch. 12 - Use PSpice or MultiSim to determine Io in the...Ch. 12 - Given the circuit in Fig. 12.67, use PSpice or...Ch. 12 - Using Fig. 12.68, design a problem to help other...Ch. 12 - Use PSpice or MultiSim to find currents IaA and...Ch. 12 - For the circuit in Fig. 12.58, use PSpice or...Ch. 12 - A balanced three-phase circuit is shown in Fig....Ch. 12 - A three-phase, four-wire system operating with a...Ch. 12 - As shown in Fig. 12.72, a three-phase four-wire...Ch. 12 - Meter readings for a three-phase wye-connected...Ch. 12 - A certain store contains three balanced...Ch. 12 - The two-wattmeter method gives P1=1200W and...Ch. 12 - In Fig. 12.73, two wattmeters are properly...Ch. 12 - If wattmeters W1 and W2 are properly connected...Ch. 12 - For the circuit displayed in Fig. 12.74, find the...Ch. 12 - Predict the wattmeter readings for the circuit in...Ch. 12 - Prob. 75PCh. 12 - Show that the I2R losses will be higher for a...Ch. 12 - A three-phase generator supplied 10 kVA at a power...Ch. 12 - Prob. 78CPCh. 12 - A balanced three-phase generator has an abc phase...Ch. 12 - A balanced three-phase source furnishes power to...Ch. 12 - A professional center is supplied by a balanced...Ch. 12 - A balanced three-phase system has a distribution...Ch. 12 - A commercially available three-phase inductive...Ch. 12 - Figure 12.76 displays a three-phase...Ch. 12 - Design a three-phase heater with suitable...Ch. 12 - For the single-phase three-wire system in Fig....Ch. 12 - Consider the single-phase three-wire system shown...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.Similar questions
- Two parallel three-phase loads are supplied from 415.7 V rms, 60 Hz three-phase supply. The loads are as follows: Load 1: Y-connected with an impedance of (80 -j 60) Q/ phase Load 2: Delta-connected with an impedance of (48 +j 36) Q/ phase Taking Van as phase reference, determine the power factor of the combined load and the line current in phase a. Select one: O a. Pf= 0.89 (lagging); la = 12.87 <-26.5° A O b. Pf= 0.982 (lèading); la = 5.209 <+10.418° A O c. Pf= 0.89 (leading); la = 12.87 <+26.5° A O d. Pf= 0.89 (leading); la = 7.415 <+26.5° A O e. Pf= 0.982 (lagging); la =5.209 <-10.418° A O f. Pf= 0.982 (leading); la = 3.007 <+10.418° A O g. None of thesearrow_forwardQuestion 3. The two parallel loads in the figure shown below are as follows. Load 1 absorbs 24 kW and 12 kVAr and Load 2 consists of a 60 ohms resistor in parallel with a capacitive reactance of 480 ohms. 1. Determine the rms magnitude of the generator voltage Vg if the load voltage Vo is 2,400 volts rms. 2. With Vo as the reference, draw a phasor diagram of the system voltages. 8 + j10 Ω + V₁, L₁ L2arrow_forwardTwo parallel three-phase loads are supplied from 415.7 V rms, 60 Hz three-phase supply. The loads are as follows: Load 1: Y-connected with an impedance of (80 -j 60) Q/ phase Load 2: Delta-connected with an impedance of (48 +j 36) 0/ phase Taking Van as phase reference, determine the power factor of the combined load and the line current in phase a. Select one: O a. Pf= 0.89 (lagging); la = 12.87 <-26.5° A O b. Pf= 0.982 (leading); la = 5.209 <+10.418° A C. Pf= 0.89 (leading); la = 12.87 <+26.5° A O d. Pf= 0.89 (leading); la =7.415 <+26.5° A O e. Pf= 0.982 (lagging); la = 5.209 <-10.418° A Of. Pf= 0.982 (leading); la = 3.007 <+10.418° A g. None of thesearrow_forward
- Obtain the equivalent circuit of a 200/400 V, 50 Hz, single-phase transformcr from the following test data: O.C. test : 200 V, 0-7 A, 70 W .. on L.V. side S.C. test : 15 V, 10 A, 85 W Calculate the secondary voltage when delivering S kW at 08 p.f. lagging, the primary voltage being . on H.V. side 200 V. (R, = 57-14 Q ; X, = 330 2; R = 0-21 Q ; Xg, = 0-31 Q ; 3778 V)arrow_forwardTwo parallel connected loads A and B are supplied by a 440 V line to line, 3-phase, 60 Hz generator. Load A draws an apparent power of 100 kVA at 0.80 pf lagging and load B draws an apparent power of 70 kVA at unity pf. Determine the line current supplied by the source.arrow_forwardQUESTION 5 Find the total real power dissipation in a balanced delta-connected system. Phase voltage is 100V RMS, load impedance is 1750, and power factor is 0.77 lagging O 132W O 507W O 2.33kW O 1.25kWarrow_forward
- ChatGPT 3.5 You A balanced load is connected in star across a 3 phase 415V 50Hz supply. The load consists of a coil of resistance 25 ohms and inductance 0.5 henry in parallel with a pure resistance of 28 ohms and a pure capacitor of 60 microfarads capacitance ib each branch Calculate I. The line currents Ii. The overall power factor. iii. The power delivered from the supply. iv. The power dissipated in the resistors and coils. v. The current in the neutral supported by a reason why its value is that deduced ?arrow_forwardA three-phase system has balanced conditions so that the per-phase circuit representation can be used as shown in Figure 1 Select the turns ratio of the step-up and step-down transformers that the system operates with an efficiency greater than 99 percent. Moreover, find the complex power (received or given) of all components in the circuit and the V1 and V2 voltages. The load voltage is specified as 4 kV rms, and the load impedance is 4/3 ohm. ..arrow_forwardA delta connected load of impedances (6 + j9) ohms each is supplied through a line having an impedance of (1 + j2) ohms. The supply voltage is balanced 3-phase, 400 V, 60 Hz mains. Find the total power drawn by the load.arrow_forward
- For the circuit show below, solve for the following: a. The complex power delivered to each passive component of the circuit b. The total impedance c. The overall power factor j30 N -j25 N elll 50/-17° V rms 10 2 15 0arrow_forwardAnswer all 1.) In a three phase Delta-Wye connection a.) What is the relationship between the line to line voltage at the source and the load? b.) What is the relationship between the Phase to Phase voltage at the load and source? c.) What is the relationship between the line Currents and phase currents going into the load? d.) What is the relationship between the power being dissipated as seen from the source compared to the load?arrow_forwardGiven: 1. 2 wye-connected loads per phase to a 3 phase power source 2. first load consists of a 55ohm resistance and a 0.05H inductance per phase 3. second load consumes 1kW and power factor of 0.7 lagging per phase 4. RMS of voltage across the loads are 220V, frequency 120Hz per phase 5. single phase equivalent is shown in the figure: Question: What is the total power drawn from the 3 phase source?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Introductory Circuit Analysis (13th Edition)Electrical EngineeringISBN:9780133923605Author:Robert L. BoylestadPublisher:PEARSONDelmar's Standard Textbook Of ElectricityElectrical EngineeringISBN:9781337900348Author:Stephen L. HermanPublisher:Cengage LearningProgrammable Logic ControllersElectrical EngineeringISBN:9780073373843Author:Frank D. PetruzellaPublisher:McGraw-Hill Education
- Fundamentals of Electric CircuitsElectrical EngineeringISBN:9780078028229Author:Charles K Alexander, Matthew SadikuPublisher:McGraw-Hill EducationElectric Circuits. (11th Edition)Electrical EngineeringISBN:9780134746968Author:James W. Nilsson, Susan RiedelPublisher:PEARSONEngineering ElectromagneticsElectrical EngineeringISBN:9780078028151Author:Hayt, William H. (william Hart), Jr, BUCK, John A.Publisher:Mcgraw-hill Education,
Introductory Circuit Analysis (13th Edition)
Electrical Engineering
ISBN:9780133923605
Author:Robert L. Boylestad
Publisher:PEARSON
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:9781337900348
Author:Stephen L. Herman
Publisher:Cengage Learning
Programmable Logic Controllers
Electrical Engineering
ISBN:9780073373843
Author:Frank D. Petruzella
Publisher:McGraw-Hill Education
Fundamentals of Electric Circuits
Electrical Engineering
ISBN:9780078028229
Author:Charles K Alexander, Matthew Sadiku
Publisher:McGraw-Hill Education
Electric Circuits. (11th Edition)
Electrical Engineering
ISBN:9780134746968
Author:James W. Nilsson, Susan Riedel
Publisher:PEARSON
Engineering Electromagnetics
Electrical Engineering
ISBN:9780078028151
Author:Hayt, William H. (william Hart), Jr, BUCK, John A.
Publisher:Mcgraw-hill Education,
What is the Difference Between Single Phase and Three Phase???; Author: Electrician U;https://www.youtube.com/watch?v=FEydcr4wJw0;License: Standard Youtube License