Question 1

A way of determining the relationships of the motion of the conductor, the magnetic field direction, and the direction of the induced current is by using the .

Accepted Answer

The left-hand generator rule is used to determine the relationships between the motion of the conductor, the magnetic field direction, and the direction of the induced current in generators.

Question 2

Losses in the core of iron core inductors include

Accepted Answer

Eddy current and hysteresis losses are the two main types of losses in the core of iron core inductors. Eddy current losses are caused by circulating currents induced in the core, while hysteresis losses are due to the lagging of magnetic domains in the core material.

Question 3

What is one device used for spike suppression in either direct or alternating current circuits?

Accepted Answer

Metal oxide varistors (MOVs) are used for spike suppression in both AC and DC circuits. They are nonlinear devices that provide a low impedance path to ground when a voltage surge occurs, thus protecting the sensitive components from damage. Voltage varistors, inductive varistors, and capacitive varistors are not commonly used for spike suppression.

Question 4

The time required for current in an inductor to reach its full Ohm's law value is called the time constant.

Accepted Answer

The time constant for an inductor is given by the formula τ = L/R, where L is the inductance and R is the resistance.

Question 5

An induced voltage opposes the motion that causes it according to .

Accepted Answer

This statement is known as Lenz's law, which states that the direction of an induced electromotive force (emf) is always such as to oppose the change in the circuit or magnetic field that produced it.

Question 6

Exponential curves are always divided into

Accepted Answer

Exponential curves are often divided into five stages: initial growth, rapid growth, slowing growth, saturation, and decline.

Question 7

During the period of time known as the first time constant of an exponential curve, the current will rise to about percent of its full value.

Accepted Answer

The first time constant is defined as the time it takes for the current to reach 63.2% of its full value. Therefore, choice D (63.2) is the correct answer.

Question 8

When a conductor cuts magnetic lines of force, a voltage is induced into the conductor. This principle is called _____.

Accepted Answer

The principle described is known as electromagnetic induction.

Question 9

The amount of voltage induced into a conductor depends on the turns of wire, the strength of the magnetic field, and the speed of cutting action.

Accepted Answer

This statement is true. The amount of voltage induced into a conductor is directly proportional to the number of turns of wire, the strength of the magnetic field, and the speed with which the magnetic field cuts across the wire. This is known as Faraday's law of electromagnetic induction.

Question 10

A coil has an inductance of 3 H and a wire resistance of 15 Ω. How long will it take for the current to reach its full value?

Accepted Answer

The time constant of an inductor (τ) is given by τ = L/R, where L is the inductance in Henrys and R is the resistance in Ohms. Plugging in the given values, τ = 3H / 15Ω = 0.2 seconds. The current reaches its full value in about 5 time constants, which is 5 * 0.2 = 1.0 seconds.

Question 11

The direction of induced current can be determined by using 's left­hand generator rule.

Accepted Answer

Fleming's left-hand generator rule is used to determine the direction of induced current in a conductor. Ohm's law is used to calculate the relationship between current, voltage, and resistance. Kirchhoff's laws are used to calculate the current and voltage in a circuit. Coulomb's law is used to calculate the force between charged particles.

Question 12

If current is flowing in a circuit containing an inductor and the power switch is opened, the magnetic field surrounding the inductor collapses and induces voltage into the inductor, resulting in a voltage spike.

Accepted Answer

This phenomenon is known as inductive kickback or back EMF. The collapse of the magnetic field generates a voltage spike that can potentially damage the circuit if not properly managed.

Question 13

When using the left-hand generator rule, the center finger points to the direction of .

Accepted Answer

The left-hand generator rule is used to determine the direction of induced current in a conductor moving through a magnetic field. According to this rule, when the thumb points in the direction of motion of the conductor (relative to the magnetic field), and the index finger points in the direction of the magnetic field, the middle finger will point in the direction of the induced current.

Question 14

If a voltage is being induced into a conductor by electromagnetic induction, reversing the direction of motion of the conductor will .

Accepted Answer

Reversing the direction of motion of the conductor will result in reversing the direction of the induced voltage. This is due to the fact that the induced voltage is directly proportional to the rate of change of magnetic field linking with the conductor, and reversing the direction of motion changes the direction of the magnetic field, thereby reversing the direction of the induced voltage.

Question 15

If a conductor is moved upward, the polarity of induced voltage is reversed and the current flows in the
_______________ direction.

Accepted Answer

The answer of If a conductor is moved upward, the...

Question 16

Inductors always a change of current.

Accepted Answer

The answer of Inductors always a change of current....

Question 17

When a closed loop of wire cuts through magnetic flux lines, a current is induced into the loop. The current in the loop sets up a magnetic field that is in opposition to the original magnetic flux. This is essentially .

Accepted Answer

This phenomenon is known as Lenz's law, which states that the direction of the induced current will be such that it opposes the change that produced it.

Question 18

What is the unit of measurement for inductance?

Accepted Answer

Inductance is measured in henry (H), named after Joseph Henry who discovered electromagnetic induction independently of Michael Faraday.

Question 19

The magnetic quantity Weber (Wb) is equal to 100,000,000 lines of flux. If a conductor cuts through one Weber per second, then a voltage of volt(s) is induced into the conductor.

Accepted Answer

The magnetic flux of one Weber (Wb) corresponds to an induced electromotive force (EMF) of one volt when it is cut by a conductor in one second, according to Faraday's law of electromagnetic induction.

Question 20

When using the left-hand generator rule, the thumb points to the direction of .

Accepted Answer

The answer of When using the left-hand generator rule, the...

Quiz 14: Magnetic Induction

A way of determining the relationships of the motion of the conductor, the magnetic field direction, and the direction of the induced current is by using the .

Losses in the core of iron core inductors include

What is one device used for spike suppression in either direct or alternating current circuits?

The time required for current in an inductor to reach its full Ohm's law value is called the time constant.

An induced voltage opposes the motion that causes it according to .

Exponential curves are always divided into

During the period of time known as the first time constant of an exponential curve, the current will rise to about percent of its full value.

When a conductor cuts magnetic lines of force, a voltage is induced into the conductor. This principle is called _____.

The amount of voltage induced into a conductor depends on the turns of wire, the strength of the magnetic field, and the speed of cutting action.

A coil has an inductance of 3 H and a wire resistance of 15 Ω. How long will it take for the current to reach its full value?

The direction of induced current can be determined by using 's lefthand generator rule.

If current is flowing in a circuit containing an inductor and the power switch is opened, the magnetic field surrounding the inductor collapses and induces voltage into the inductor, resulting in a voltage spike.

When using the left-hand generator rule, the center finger points to the direction of .

If a voltage is being induced into a conductor by electromagnetic induction, reversing the direction of motion of the conductor will .

If a conductor is moved upward, the polarity of induced voltage is reversed and the current flows in the _______________ direction.

Inductors always a change of current.

When a closed loop of wire cuts through magnetic flux lines, a current is induced into the loop. The current in the loop sets up a magnetic field that is in opposition to the original magnetic flux. This is essentially .

What is the unit of measurement for inductance?

The magnetic quantity Weber (Wb) is equal to 100,000,000 lines of flux. If a conductor cuts through one Weber per second, then a voltage of volt(s) is induced into the conductor.

When using the left-hand generator rule, the thumb points to the direction of .

Quiz 14: Magnetic Induction

A way of determining the relationships of the motion of the conductor, the magnetic field direction, and the direction of the induced current is by using the .

Losses in the core of iron core inductors include

What is one device used for spike suppression in either direct or alternating current circuits?

The time required for current in an inductor to reach its full Ohm's law value is called the time constant.

An induced voltage opposes the motion that causes it according to .

Exponential curves are always divided into

During the period of time known as the first time constant of an exponential curve, the current will rise to about percent of its full value.

When a conductor cuts magnetic lines of force, a voltage is induced into the conductor. This principle is called _____.

The amount of voltage induced into a conductor depends on the turns of wire, the strength of the magnetic field, and the speed of cutting action.

A coil has an inductance of 3 H and a wire resistance of 15 Ω. How long will it take for the current to reach its full value?

The direction of induced current can be determined by using 's left­hand generator rule.

If current is flowing in a circuit containing an inductor and the power switch is opened, the magnetic field surrounding the inductor collapses and induces voltage into the inductor, resulting in a voltage spike.

When using the left-hand generator rule, the center finger points to the direction of .

If a voltage is being induced into a conductor by electromagnetic induction, reversing the direction of motion of the conductor will .

If a conductor is moved upward, the polarity of induced voltage is reversed and the current flows in the _______________ direction.

Inductors always a change of current.

When a closed loop of wire cuts through magnetic flux lines, a current is induced into the loop. The current in the loop sets up a magnetic field that is in opposition to the original magnetic flux. This is essentially .

What is the unit of measurement for inductance?

The magnetic quantity Weber (Wb) is equal to 100,000,000 lines of flux. If a conductor cuts through one Weber per second, then a voltage of volt(s) is induced into the conductor.

When using the left-hand generator rule, the thumb points to the direction of .

The direction of induced current can be determined by using 's lefthand generator rule.