5. Magnetism & Electromagnetism Flashcards
The small magnet created by an electron orbit is called a:
magnetic induction
magnetic pole
insulator
magnetic dipole
magnetic dipole
With regards to mutual induction, the coil in which current is induced is called the:
primary coil
secondary coil
capacitor
generator
secondary coil
When ferromagnetic material, such as iron, is brought within the lines of force of a strong magnet, the dipoles of the ferromagnetic material will temporarily align themselves with the lines of force passing through the iron bar. This process is termed:
magnetic induction
spin magnetic moment
mutual induction
alternating current (AC)
magnetic induction
As electrons travel along a conductor (as current flows), a magnetic field is generated _____________ to the electrons’ direction of motion.
Perpendicular
Parallel
In the same direction
There is no magnetic field generated in this example
Perpendicular
One generator armature revolution is equal to one cycle. One cycle per second (cps) is equal to:
1 Hertz
1 XL
1 Weber
1 Tesla
1 Hertz
As the number of turns, or loops of a solenoid increases when part of a powered circuit, what increases around the coil?
flux density
lines of flux
magnetic field lines
All of these
All of these
The strength of the induced current produced inside a conductor when the magnetic lines of force and a conductor are in motion relative to each other can be affected by:
The strength of the magnetic field
The speed of the motion between lines of force and the conductor
The angle between the magnetic lines of force and the conductor
The number of turns in the conducting coil
All of these
All of these
This device consists of a wire wrapped around an iron core, with the iron core serving to greatly increase the intensity of the magnetic field.
generator
compass
filament
electromagnet
electromagnet
As the AC generator armature rotates from 180° to 270° through the magnetic field, describe what happens to the electromagnetic force (emf or voltage) produced in the circuit.
It is increasing to peak voltage
It is decreasing to 0 voltage
Voltage doesn’t fluctuate in an AC circuit
All of these
It is increasing to peak voltage
As a conductor is passed through a magnetic field, or a magnetic field is passed through a conductor, what part of the atom that comprises the conductor is induced to move?
Protons
Neutrons
Compounds
Electrons
Electrons
When two coils are placed in close proximity and alternating current (AC) supplied to the first coil induces a similiar flow in the second coil, this is termed:
retentivity
mutual induction
electron spin
direct current (DC)
mutual induction
As the AC generator armature rotates from 90° to 180° through the magnetic field, describe what happens to the electromagnetic force (emf or voltage) produced in the circuit.
It is increasing to peak voltage
It is decreasing to 0 voltage
Voltage doesn’t fluctuate in an AC circuit
All of these
It is decreasing to 0 voltage
A generator, or dynamo, is a device that converts mechanical energy to electrical energy. When observing the alternating current (AC) sine wave, at what two generator phase angles is the maximum amount of voltage being produced inside the conductor?
90°,270°
0°,360°
45°,135°
180°,360°
90°,270°
How many times per second do the electrons in a 50-Hz alternating current (AC) change their direction of movement?
120
180
100
360
100
Electric current in the United States is supplied at a frequency of
90 Hz
50 Hz
60 Hz
120 Hz
60 Hz
