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# Power Engineering

### Electrical networks

Engine consumes 5kw of power and a reactive power of 2kvar at current of (3+j2) Amps. Find the applied voltage in complex form V=(a+jb). Then use P=Re(VI*) and Q=IM(VI*) to form two simultaneous equations. Please show workings.

### AM Wave and Power

Consider the message signal: m(t) = 20 cos (2*pi*t) volts and the carrier wave: c(t) = 50 cost(100*pi*t) volts a. Sketch (to scale) the resulting AM wave for 75% of the modulation b. Find the power developed across a load of 100 ohms due to this AM wave.

### Voltage in complex forms

An engine consumes 10kw of power and 4kvar reactive power at a current of (6+j4)Amps . Find the applied voltage in complex form using P=Re(VI) and Q=Im(VI) as simultaneous equations. Obviously V=(a+jb)

### Solving for Power

If the voltage and current supplied to a circuit or load by a source are: Vs = 170<(-0.157) V Is = 13<0.28 A determine a) The power supplied by the source which is dissipated as heat or work in the circuit (load). b) The power stored in reactive components in the circuit (load). c) The power factor angle and power facto

### Power Factor: Solving for Circuits

Determine C so that the plant power factor of Figure P7.25 (see attached file) is corrected to 1 (or the power factor angle to zero) so that Is is minimized and in phase with Vo. vs(t) = 450cos(wt) V w = 377 rad/s Z = 7 < 0.175 &#937;

### Maximum Power Theorem

A) Find the Thevenin's circuit for the circuit shown in Fig. 5.1 (see attachment) similar to the circuit shown in Fig. 5.2 (see attachment). b) Calculate the output voltage for different load resistors and the corresponding power and enter these values in Table 1. c) Plot a graph of load resistance vs power using Matlab (

### Complex power of electrical load

An electrical load operates at 240 Vrms. The load absorbs an average power of 8kW with 0.8 lagging power factor. How do I compute the complex power of the load and impedance?

### Shunt resistance effect in a voltage divider

What is the effect of the DMM input resistance on the measured results? Derive the voltage gain of the divider with a DMM resistance of Rm, which is also called shunt resistance (See Figure 2.3-attached file).

### Current, Power and Total Power

See the attached file. For the circuit shown in Figure 2.24 (attached file), find: a) The currents i1 and i2. b) The power delivered by the 3-A current source and by the 12-V voltage source. c) The total power dissipated by the circuit. Let R1=25 ohms, R2= 10 ohms, R3= 5 ohms, R4= 7 ohms, and express i1 and i2 as function

### Terminal Voltage & Power Supplied/Dissipated

Refer to Figure 2.16 (see attached file): a) Find the total power supplied by the ideal source. b) Find the power dissipated and lost within the nonideal source. c) What is the power supplied by the source to the circuit as modeled by the load resistance? d) Plot the terminal voltage and power supplied to the circuit as a fu

### Supplying and Dissipating Power

Determine which elements in the circuit of Figure 2.10 (attached file) are supplying power and which are dissipating power. Also, determine the amount of power dissipated and supplied.

### An amplifier with a voltage gain of +30db, an input resistance of 8 k ohms, and an output resistance of 2 k ohms is used to drive

An amplifier with a voltage gain of +30db, an input resistance of 8 k ohms, and an output resistance of 2 k ohms is used to drive a 2 k ohm load. What is the value of Avo? a. 3.162 b. 31.62 c. 100 d. 1000

### Star vs Delta for pf correction capacitors

Comment on the difference between pf correction capacitors connected in star and delta.

### Capacitance

Prior to t=0, a 100- uF capacitance is uncharged. Starting at t=0, the voltage across the capacitor is increased linearly with time to 100V in 2s. Then, the voltage remains constant at 100V. Sketch the voltage, current, power, and stored energy to scale versus time. Please show equations for the sketches.

### Voltage through 3-uF Capacitance

The current through a 3-uF capacitance is shown in the attachment. At t=0, the voltage is v(0)=10v. Sketch the voltage, power, and stored energy to scale vs. time. In the sketch of each one, I need the equations worked out for each plot. (See attached file for full problem description).

### Circuit Elements - Power Dissipated

Given the circuit shown in the attachment find: values and power dissipated. (Please see attachment for complete question and diagram. Thanks)

### Circuit Variable Problem - Time and Power

Please see the attached. The voltage and current at the terminals of the circuit element in Fig. 1.5 are zero for... (continued in the attachment).

### Circuit Analysis

An electric load operates at 240 volts. The load absorbs an average power of 8Kw at a lagging power factor of 0.8. a) Calculate the complex power of the load b) Calculate the impedance of the load

### Rankine Cycle - Net Power, Thermal Efficiency and Heat Transfer

Water is the working fluid in a vapor power cycle with reheat, superheat and reheat. Superheated steam enters the first turbine stage at 8 MPa, 480 C and expands to 0.7 MPa. It then is reheated to 480 C before entering the second turbine stage, where it expands to the condenser pressure of 8 KPa. The mass flow rate of steam e

### Complex Power and Impedance

Question: An electrical load operates at 240 volts rms. The load absorbs an average power of 8 kW at a lagging power factor of 0.8. a) Calculate the complex power of the load. b) Calculate the impedance of the load. Please view attachment for multiple choice options.

### Dissipations of Power in Lightbulbs

An incandescent lightbulb rated at 100 W will dissipate 100 W as heat and light when connected across a 110-V ideal voltage source. If three of these bulbs are connected in series across the same source, determine the power each bulb will dissipate.

### Reactive Power Absorbed by a Line

Two balanced, in parallel connected, three-phase loads are fed by a three-phase line with an impedance of (2+j4) Ohm per phase. The first load is delta-connected with an impedance of (60 ? j45) Ohm per phase, and the second load is Y-connected with an impedance of (30 + j40) Ohm per phase. The line is energized at the sending en

### Power Plants - Burning Coal

See attached file.

### Turbine Unit and Mechanical Output Generated

An area of an interconnected 60 hz power system has three turbine generator units rated 100MVA, 200MVA, and 600MVA respectively. Regulation constants are given for each unit, with the load suddenly decreasing by 100MW. With assumptions made and a frequency response of beta = 165 p.u., calculate the MW decrease in mechanical ou

### A Three-Phase Overhead Transmission Line

A three-phase overhead transmission line line has a per-phase resistance of 0.15 ohm/km and a per-phase inductance of 1.3263 mH/km. Assume that the shunt capacitance is negligible. The length f the line is 40 kilometers and it operates under 220 kV and 60-Hz. The line is supplying a three-phase load of 381 MVA at 0.8 power facto

### Real Power Generated and Total Real Power Losses

Consider the electric power system show {see attachment}. The power-flow solution of this system can be obtained without resorting to iterative techniques. The elements of the bus admittance matrix Ybus have been calculated as attached. If sigma_2 = 16.97 degrees and sigma_3 = 21 degrees, calculate the real power generated a

### Power-Flow Solution (Calculate Phase Angle via Real and Reactive Power Equations)

Consider the electric power system shown {see attachment}. The power-flow solution of this system can be obtained without resorting to iterative techniques. The elements of the bus admittance matrix Ybus have been calculated as: {see attachment}. Calculate the phase angle {see attachment} by using the real and reactive power