Rio Salado PHY 112 Final Questions
and Verified Solutions 100% Correct
Answers Already Graded A+
QUESTIONS AND ANSWERS
When an iron bar is moved through a uniform magnetic field, what happens to the charge
carriers within the bar? ANSWER -Negative charge carriers move relatively freely while
the positive charge carriers do not
How does the induced EMF in a conductor moving through a magnetic field affect charge
distribution? ANSWER -It increases the charge separation
How is flux defined in the context of magnetic fields? ANSWER -The measure of the
number of magnetic field lines passing through a given area
What doe Lenz's Law state regarding the direction of induced current? ANSWER -The
induced current flows in the opposite direction of the changing flux
What does Faraday's Law state regarding the relationship between induced EMF and the
rate change of flux ANSWER -The induced EMF is directly proportional to the rate of
change of flux
According to Faraday's law, what happens to the direction of the induced EMF with respect
to the change in flux? ANSWER -It is opposite to the change in flux
In the context of Faraday's law, what does the negative sign in the equation signify?
ANSWER -It signifies the direction of the induced EMF
What is the magnitude of the induced EMF across a metal bar (32cm) moved through a 0.30
T magnetic field and 23m/s? ANSWER -Example work: BLvcos() =
(0.30T)(0.32m)(23m/s) = 2,208 = 2.2V
, What is the fundamental difference between motors and generators? ANSWER -Motors
convert electric energy into work, while generators convert work into electric energy.
According to Faraday's law, what induces an EMF in a generator? ANSWER -Change in
the angle between the loop and the magnetic field
According to. Faraday's law, what induces an EMF in a motor? ANSWER -Change in
number of loops
How does Lenz's law effect the operation of a generator? ANSWER -It induces and EMF
that opposes the original current through the loop
How does Lenz's law effect the operation of a motor? ANSWER -the EMF, opposes any
change, so that the input EMF that powers the motor will be opposed by the motor's self-
generated EMF, called the back EMF of the motor.
What is the purpose of a transformer in an electrical circuit? ANSWER -To change the
voltage in a circuit
What did Maxwell's electromagnetic theory demonstrate? ANSWER -The wave nature of
electricity and magnetism
Which equation describes the nature and behavior of magnetic field lines? ANSWER -
Grauss's Law of magnetism
What does Ampere's circuit law describe? ANSWER -how magnetic fields are created by
moving charges or changing electric fields
How are electric and magnetic waves related according to Maxwell's equation? ANSWER -
They occur together and travel perpendicular to each other
What is the relationship between the speed and on EM wave and the amplitude of the
electric and magnetic fields? ANSWER -Speed is directly proportional to the amplitude of
the electric field
and Verified Solutions 100% Correct
Answers Already Graded A+
QUESTIONS AND ANSWERS
When an iron bar is moved through a uniform magnetic field, what happens to the charge
carriers within the bar? ANSWER -Negative charge carriers move relatively freely while
the positive charge carriers do not
How does the induced EMF in a conductor moving through a magnetic field affect charge
distribution? ANSWER -It increases the charge separation
How is flux defined in the context of magnetic fields? ANSWER -The measure of the
number of magnetic field lines passing through a given area
What doe Lenz's Law state regarding the direction of induced current? ANSWER -The
induced current flows in the opposite direction of the changing flux
What does Faraday's Law state regarding the relationship between induced EMF and the
rate change of flux ANSWER -The induced EMF is directly proportional to the rate of
change of flux
According to Faraday's law, what happens to the direction of the induced EMF with respect
to the change in flux? ANSWER -It is opposite to the change in flux
In the context of Faraday's law, what does the negative sign in the equation signify?
ANSWER -It signifies the direction of the induced EMF
What is the magnitude of the induced EMF across a metal bar (32cm) moved through a 0.30
T magnetic field and 23m/s? ANSWER -Example work: BLvcos() =
(0.30T)(0.32m)(23m/s) = 2,208 = 2.2V
, What is the fundamental difference between motors and generators? ANSWER -Motors
convert electric energy into work, while generators convert work into electric energy.
According to Faraday's law, what induces an EMF in a generator? ANSWER -Change in
the angle between the loop and the magnetic field
According to. Faraday's law, what induces an EMF in a motor? ANSWER -Change in
number of loops
How does Lenz's law effect the operation of a generator? ANSWER -It induces and EMF
that opposes the original current through the loop
How does Lenz's law effect the operation of a motor? ANSWER -the EMF, opposes any
change, so that the input EMF that powers the motor will be opposed by the motor's self-
generated EMF, called the back EMF of the motor.
What is the purpose of a transformer in an electrical circuit? ANSWER -To change the
voltage in a circuit
What did Maxwell's electromagnetic theory demonstrate? ANSWER -The wave nature of
electricity and magnetism
Which equation describes the nature and behavior of magnetic field lines? ANSWER -
Grauss's Law of magnetism
What does Ampere's circuit law describe? ANSWER -how magnetic fields are created by
moving charges or changing electric fields
How are electric and magnetic waves related according to Maxwell's equation? ANSWER -
They occur together and travel perpendicular to each other
What is the relationship between the speed and on EM wave and the amplitude of the
electric and magnetic fields? ANSWER -Speed is directly proportional to the amplitude of
the electric field
