Fundamentals of Electrical Engineering 1st. Edition by Giorgio Rizzoni | 9780073380377 | 0073380377

Basic Electrical

Fundamentals of Electrical Engineering

6 SOLVED PROBLEMS

205 SOLVED PROBLEMS

Question: 7.9

Can a Series Capacitor Be Used for Power Factor Correction? The circuit of Figure 7.21 proposes the use of a series capacitor to perform power factor correction. Show why this is not a feasible alternative to the parallel capacitor approach demonstrated in Example 7.8. ...

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Known Quantities: Source voltage; load impedance. ...

Question: 7.7

Complex Power and Power Triangle Find the reactive and real power for the load of Figure 7.16. Draw the associated power triangle. ...

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Known Quantities: Source voltage; load impedance. ...

Question: 7.4

Complex Power Calculations Use the definition of complex power to calculate real and reactive power for the load of Figure 7.12. ...

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Known Quantities: Source, load voltage and current...

Question: 7.2

Computing Average AC Power Compute the average power dissipated by the load of Figure 7.7. ...

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Known Quantities: Source voltage, internal resista...

Question: 4.5

Calculating Inductor Current from Voltage Calculate the current through the inductor from knowledge of the terminal voltage and of the initial current. ...

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Known Quantities: Inductor voltage; initial condit...

Question: 2.1

Charge and Current in a Conductor Find the total charge in a cylindrical conductor (solid wire) and compute the current flowing in the wire. ...

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Known Quantities: Conductor geometry, charge densi...

Question: 7.6

Real Power Transfer for Complex Loads Use the definition of complex power to calculate the real and reactive power for the load of Figure 7.14. Repeat the calculation when the inductor is removed from the load, and compare the real power transfer between source and load for the two cases. ...

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Known Quantities: Source voltage and resistance; l...

Question: 7.12

Ideal Transformer Turns Ratio We require a transformer to deliver 500 mA at 24 V from a 120-V rms line source. How many turns are required in the secondary? What is the primary current? ...

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Known Quantities: Primary and secondary voltages; ...

Question: 5.17

Transient Response of Automotive Ignition Circuit The circuit shown in Figure 5.54 is a simplified but realistic representation of an automotive ignition system. The circuit includes an automotive battery, a transformer³ (ignition coil), a capacitor (known as condenser in old-fashioned automotive ...

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Known Quantities: Battery voltage, resistor, capac...

Question: 13.13

A Loudspeaker A loudspeaker, shown in Figure 13.47, uses a permanent magnet and a moving coil to produce the vibrational motion that generates the pressure waves we perceive as sound. Vibration of the loudspeaker is caused by changes in the input current to a coil; the coil is, in turn, coupled ...

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Known Quantities: Circuit and mechanical parameter...

Question: B.1

Complex Frequency Notation Use complex impedance ideas to determine the response of a series RL circuit to a damped exponential voltage. ...

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Known Quantities: Source voltage, resistor, induct...

Question: 13.11

Transient Response of a Solenoid Analyze the current response of the solenoid of Example 13.10 to a step change in excitation voltage. Plot the force and current as a function of time. ...

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Known Quantities: Coil inductance and resistance; ...

Question: 13.12

A Relay Figure 13.41 depicts a simplified representation of a relay. Determine the current required for the relay to make contact (i.e., pull in the ferromagnetic plate) from a distance x. ...

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Known Quantities: Relay geometry; restoring force ...

Question: 13.10

A Solenoid Figure 13.35 depicts a simplified representation of a solenoid. The restoring force for the plunger is provided by a spring. 1. Derive a general expression for the force exerted on the plunger as a function of the plunger position x. 2. Determine the mmf required to pull the plunger ...

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Known Quantities: Geometry of magnetic structure; ...

Question: 13.9

An Electromagnet An electromagnet is used to collect and support a solid piece of steel, as shown in Figure 13.33. Calculate the starting current required to lift the load and the holding current required to keep the load in place once it has been lifted and is attached to the magnet. ...

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Known Quantities: Geometry, magnetic permeability,...

Question: 13.8

Impedance Transformer Find the equivalent load impedance seen by the voltage source (i.e., reflected from secondary to primary) for the transformer of Figure 13.30. ...

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Known Quantities: Transformer turns ratio α. Find...