Chapter 8 Quiz :) (study guide), Chapter 9 Study

See Figure 8.5. Which of the following terms describes the voltage across the 7Ω resistor when using the mesh analysis (general) approach?

(7 Ω)(I1 - I2)

See Figure 8.3. What is VS?

+6 V

See Figure 9.4. What is the Norton equivalent current IN?

.67 A

See Figure 8.4. If the branch current method is used, which equation describes loop 1?

0 = -5V + (3 Ω)I1 - (7 Ω)I2

See Figure 9.2. Using the superposition theorem, what is the portion of the current through the 6 Ω resistor caused by the 8 V battery?

0 A

See Figure 9.5. What value of R2 makes these two circuits equivalent substitutions between terminals a and b?

10 Ohm

See Figure 9.3. Using Millman's theorem, what is Req, external to the load?

10 Ohms

See Figure 8.1. When converted to a voltage source, the equivalent series resistance is

10 ohms

See Figure 9.1. What is the Thevenin resistance external to the resistor R?

12 Ohms

See Figure 8.7, transform the 2 amp current source in parallel with the 6 ohm resistor to a voltage source and a resistor.

12 volt source in series with a 6 ohm resistor

See Figure 9.4. What is the Norton equivalent resistance RN external to the resistor R?

15 Ohm

Leon-Charles Thevenin died in

1927

See Figure 8.5. If nodal analysis were to be used to solve for unknown voltages in this circuit, how many nodes would be needed (including the reference node)?

2

See Figure 8.1. What is IL?

29.7 mA

See Figure 9.1. What is the Thevenin voltage external to the resistor R?

3.3 V

See Figure 8.6. What value of R will result in a balanced bridge?

30 Ohms

See Figure 8.1. When converted to a voltage source, the equivalent voltage is

30V

In nodal analysis, how many equations will need to be solved if the circuit contains five nodes (including the reference node)?

4

See Figure 8.5. Transform the 5 volt source and the 3 ohm resistor to a current source and a resistor.

5/3 amp current source in parallel with a 3 ohm resistor

See Figure 8.5. The equation obtained from performing mesh analysis on mesh #1 is:

5V + 3I1 + 7(I1 - I2) = 0

When Rint is equal to RL, which of the following will occur?

A load will receive maximum power.

Which of the following is true of a series, open circuit?

A voltage can be read, but current will be zero.

An ideal current source has a 0 Ω resistance in parallel with it.

False

An ideal current source would have ten ohms of resistance.

False

An ideal voltage source has an infinite resistance in series with it.

False

Current sources of different amplitudes can be connected in series.

False

In the superposition method, you replace a current source with a short circuit.

False

Norton's theorem permits the reduction of any two-terminal linear dc network to one having a single current source and a series resistance.

False

The magnitude and polarity of the voltage across a current source is not a function of the network to which it is attached.

False

The primary difference between the equivalent circuit of Norton and Thevenin is that Nortons consists of voltage and a series resistor.

False

The superposition principle is applicable to power effects because the power loss in a resistor varies as the square of the current.

False

The total power delivered to a resistive element can be determined by the sum of the power levels established by each source.

False

To perform a conversion from one type of source to another, a voltage source must have a resistor in parallel with it and a current source must have a resistor in series.

False

Under maximum power transfer conditions, the operating efficiency of a system is 100%

False

When using mesh analysis, each loop must be drawn in the clockwise direction.

False

When using the superposition theorem, each ideal voltage and current source must be replaced by an open circuit.

False

See Figure 8.4. The equation for I2 in terms of I3 and I1 is:

I2 = I3 - I1

See Figure 8.4. Which equation describes node X?

I3 = I2 + I1

The mesh-analysis approach eliminates the need to substitute the results of Kirchhoff's current law into the equations derived from the results of:

KVL

When using the mesh analysis, which of the following describes the sign required if the current loop passes from the positive to the negative terminal?

Negative Sign

Which of the following describes a junction of two or more branches, where a branch is any combination of series elements?

Node

Which one of these network theorems states that any two-terminal linear bilateral dc network can be replaced by a current source and a parallel resistor?

Norton's Theorem

Which theorem states that any branch voltage can be replaced by a branch current as long as the voltage drop across the branch and current through the branch remain the same?

Substitution Theorem

Which network theorem states "The current through, or voltage across, an element in a linear bilateral network is equal to the algebraic sum of the currents or voltages produced independently by each other"?

Superposition

Under maximum power transfer conditions, which one is true?

The Thevenin resistance of the source equals the equivalent resistance of the load.

For a two-source network, if current produced by one source is in one direction, while the current produced by the other source is in the opposite direction through the same resistor, the resulting current is?

The difference between the two and has the same direction

See Figure 8.5. Which statement is true if the loop current I2 is found to be a negative number?

The original direction assumed for I2 is wrong.

See Figure 8.3. If the 2 Ω resistor short circuits, what would happen to the voltage across the 10 Ω resistor?

The voltage would stay the same

Which network theorem states "Any two-terminal, linear bilateral dc network can be replaced by an equivalent circuit consisting of a voltage source and a series resistor"?

Thevenin's

Which one of these statements is true of two or more current sources in parallel?

They may be replaced by one current source

A current source determines the current in the branch in which it is located.

True

Any node including the effect of elements tied only to other nodes is referred to as a supernode.

True

For any physical network, the value of Eth can be determined experimentally by measuring the open-circuit voltage across the load terminals.

True

From the application of Kirchhoff's voltage law, around a closed loop the polarity of a voltage source is unaffected by the direction of the assigned loop currents.

True

Source conversions are equivalent only at their external terminals.

True

The Norton and Thevenin equivalent circuits can be found from each other by using source transformation.

True

The resistance calculated using Norton's theorem is equal to the resistance calculated using Thevenin's theorem for the same electrical network.

True

Thevenin's theorem permits the reduction of any two-terminal linear dc network to one having a single voltage source and series resistance.

True

Which of the following describes a network that is popular wherever detection of small changes in quantity is required?

Wheatstone Bridge

Norton's theorem states that you can replace a 2-terminal dc network with an equivalent circuit consisting of

a current source and a parallel resistor.

See Figure 8.2. The two current sources are equivalent to

a single 4 A source in parallel with a resistor.

Thevenin's theorem states that you can replace a 2-terminal dc network with an equivalent circuit consisting of

a voltage source and a series resistor.

Millman's theorem states that

any number of parallel voltage sources can be reduced to a single source.

In the superposition method, you replace a voltage source with an open circuit.

false

The substitution theorem states that

if the voltage across and the current through a branch are known, the branch can be replaced by a combination of elements that maintain the same voltage across and current through that branch.

Thevenin's theorem states that the Thevenin voltage is equal to

open circuit voltage at the network terminals.

Power effects in a dc network cannot be determined using superposition because

power is proportional to the square of the current or voltage

Which theorem is limited to use in single-source networks?

reciprocity theorem

The reciprocity theorem states that

the current in any branch of a network, due to a single voltage source elsewhere in the network, will equal the current through the branch in which the source was originally located if the source is placed in the branch in which the current was originally measured.

When using the superposition theorem on a two-source network, if the current produced by one source is in one direction, while that produced by the other source is in the opposite direction through the same resistor,

the resulting current is the difference of the two and has the direction of the larger current

A loop current is a branch current only when it is the only loop current assigned to that branch.

true

The efficiency of a system is defined by the ratio of the power delivered to the load to all the power supplied by the source.

true

The reciprocity theorem is applicable only to single-source networks.

true

Which one of the following techniques would allow the calculation of RT in the circuit of Figure 8.6?

Δ-to-Y conversion