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WorksheetsAC Questions Unit 13 Practice
Total questions: 55
Worksheet time: 1hrs 8mins
The direction of the current flow in a current carrying conductor determines the (a) of the magnetic field around the conductor.
The amount of current flow in a current carrying conductor determines the (a) of the magnetic field around the conductor.
_____________________ ____________________ occurs whenever a voltage is produced by lines of magnetic flux cutting a conductor.
_______________ _________________ _________________ ____________ is used to determine the relationship of the motion of the conductor in a magnetic field to the direction of the induced current.
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 _________ volts is induced into the conductor.
One
Four
Five
Ten
Magnetic lines of force are called (a) .
A (a) is a quantity of electrons equal to 6.25 X 1018.
Draw the direction of the magnetic fields for the following current carrying conductors.
Current is flowing out of the page for conductor____________ and into the page for conductor______________.
Use the left hand generator rule to determine the direction of the induced currents in the following. Arrows indicate the direction the conductor is moved through.
What three factors determine the amount of induced voltage?
A heater has a resistance of 3.5Ω and is connected to a 240v source what is the power produced by the heater?
In order to generate one volt in a conductor the conductor must cut one (a) per second.
The time required for current in an inductor to reach its full Ohm's law value is called the (a) time constant.
A weber is equal to (a) lines of magnetic flux.
When current flows through a coil a _______________ _______________ is created around the coil.
(a)
According to _____________ ____________ an induced voltage or current opposes the motion that caused it.
(a)
An induced voltage is always opposite in (a) to the applied voltage.
The _____________ _____________ ____________ is a bidirectional device used for spike suppression.
Losses in the core of iron core inductors include __________ and ________ losses.
Eddy current
hysteresis
A series circuit consists of a 20 Ω, 30Ω, and a 40 Ω resistor. The 30Ω resistor has a current of 500mA. What is the total current?
A series circuit consists of a 20Ω, 30Ω, and a 40Ω resistor. The 40Ω resistor has a current of 200mA. What is the voltage across the 20Ω resistor?
When using the left-hand generator rule, the center finger points to the direction of __________.
flux
current
power
An exponential curve is divided into (a) time constants.
The unit of measurement for (a) is the henry (H).
T or F Inductors oppose current.
True
False
(a) is the property of an electrical circuit that opposes a change in current.
The unit of inductance is the (a) .
A ________________ __________________ may occur when the current through an inductor suddenly stops.
(a)
Current through a _________________ load will rise to its maximum value instantly when voltage is applied and will rise exponentially through a _________________ load due to the effect of the induced voltage.
resistive
inductive
Inductance is represented by the letter (a) .
Metal oxide varistors change their _______________ when the ______________ reaches a certain level.
resistance
voltage
T or F Inductors are electromagnets.
True
False
T or F The amount of voltage induced into a conductor depends on the turns of, the strength of the magnetic, and the speed of the cutting action.
True
False
The amount of inductance of a coil is determined by its (a) properties.
What are the four physical characteristics that determine the amount of inductance of a coil?
A coil wound around a nonmagnetic material is considered a/an (a) inductor.
When using the left-hand generator rule, the thumb points to the direction of (a) .
What is permeability?
T or F 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.
True
False
An induced voltage opposes the motion that causes it according to (a) .
Soft iron has____________________ permeability while copper has________________ permeability.
high
low
A coil has an inductance of 3H and a wire resistance of 40Ω. (A) How long will it take for the current to reach 63.2% of its maximum value? (B) How long will it take for the current to reach the maximum value?
A (a) acts like an electric check valve.
The direction of induced current can be determined by using (a) left-hand generator rule.
A _______________ _________________ has a forward voltage drop of approximately 0.7V.
(a)
When a diode is reverse biased it acts like an (a) switch.
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
When a diode is forward biased it acts like a (a) switch.
When used for voltage spike protection, diodes will work on ________________ voltages but not on ________________ voltages.
AC
DC
Voltage spikes caused by collapsing magnetic fields can reach _____________ or even _______________ of volts.
thousands
millions
When a conductor cuts magnetic lines of force, a voltage is induced into the conductor. This principle is called ______________.
Metal oxide resistors can change their resistance from several hundred thousand ohms to a low resistance in less than (a) .
MOV's are connected across coils of ______________ and ______________ ______________ to prevent voltage spikes from being induced back into the line.
inductors
transformers
MOV's are used in _______________ ________________ to protect home appliances.
