Question 1

Before the power factor of a motor can be corrected, what must be determined first?

Accepted Answer

Before the power factor of a motor can be corrected, it must first be determined how much out of phase current and voltage are with each other.

Question 2

In ____________________ circuits, the current triangle is divided by the reference vector V to obtain the impedance triangle.

Accepted Answer

parallel

Question 3

What are two important differences between series and parallel circuits, which can be seen by looking at the magnitudes of the currents and impedances?

Accepted Answer

1. The current is at a maximum in a series resonant circuit and at a minimum in a parallel resonant circuit.
2. The impedance is at a minimum in a series resonant circuit and at a maximum in a parallel resonant circuit. These factors make parallel resonance a useful feature in tuned circuits.

Question 4

In ____________________ circuits, the voltage triangle is divided and multiplied by current to obtain the impedance and power triangles, respectively.

Accepted Answer

The answer of In ____________________ circuits, the voltage triangle is...

Question 5

How do we know that a voltage vector is a reference vector?

Accepted Answer

The answer of How do we know that a voltage...

Question 6

The power factor of the circuit is found by the use of the expression: PF = P + VI.

Accepted Answer

The power factor (PF) of a circuit is calculated using the expression PF = P / (VI), where P is the real power in watts, V is the voltage in volts, and I is the current in amperes.

Question 7

The amount of reactive power or VARs (volt-amperes-reactive) can be determined using the formula: VARs = P/VA.

Accepted Answer

The correct formula to determine reactive power (VARs) is VARs = √(VA^2 - P^2), where VA is the apparent power in volt-amperes and P is the real power in watts.

Question 8

The voltage across any branch circuit in a parallel arrangement is the same as the ____________________ voltage.

Accepted Answer

The answer of The voltage across any branch circuit in...

Question 9

Before you can calculate the amount of capacitance that is needed, what must you first determine?

Accepted Answer

The answer of Before you can calculate the amount of...

Question 10

In a series circuit at the ____________________ point, the effects of inductive reactance and capacitive reactance cancel each other.

Accepted Answer

The answer of In a series circuit at the ____________________...

Question 11

What are the advantages of unity power factor?

Accepted Answer

The answer of What are the advantages of unity power...

Question 12

Nearly all commercial, industrial, and residential power circuits are connected in parallel.

Accepted Answer

Parallel circuits are used in most electrical systems because they allow each device to operate independently of the others, ensuring that if one device fails, it does not affect the operation of the others. This configuration also allows for consistent voltage across all devices.

Question 13

The apparent power or volt-amperes of the circuit can be determined by multiplying the applied voltage by the total current.

Accepted Answer

Apparent power, measured in volt-amperes (VA), is calculated by multiplying the applied voltage (V) by the total current (I) flowing in the circuit, without considering the phase angle between them.

Question 14

The current in a series circuit reaches its maximum value at ____________________.

Accepted Answer

The answer of The current in a series circuit reaches...

Question 15

The total (line) current for an ac parallel circuit may not be equal to the arithmetic sum of the current in each of the branch circuits.

Accepted Answer

In an AC parallel circuit, the total current is the vector sum of the individual branch currents, not the arithmetic sum, due to the phase differences between the currents in each branch.

Quiz 8: Ac Parallel Circuits