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14 Fundamentals of Electricity: Unit 14 - Magnetic Induction Quiz with
Verified Answers
The unit of inductance is the _____. - -henry (H)
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 _____. - -
Lenz's Law
The direction of induced current can be determined by
using the _____ left-hand generator rule. - -
Fleming's
One device used for spike suppression in either direct or
alternating current circuits is the _____ _____ _____. -
-metal oxide varistor (MOV)
The magnetic quantity Weber (Wb) is equal to
100,000,000 lines of flux. If a conductor cuts through 1
Weber per second (1 Wb/s), then a voltage of _____
volt(s) is induced into the conductor. - -1
If a voltage is being induced into a conductor by
electromagnetic induction, reversing the direction of
motion of the conductor will _____. - -reverse the
polarity
If a permanent magnet is first pushed into a coil of wire
and then pulled out of the coil, the two voltages induced
(one for each direction of magnet movement) will be
_____. - -opposite in polarity
* If a DC voltage is connected to an inductor, during the
period of time called the first time constant, the current will
rise to about _____ % of its full value. - -63.2%
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 _____. - -left-
hand generator
If a voltage is being induced into a conductor by
electromagnetic induction, reversing the direction of the
magnetic field will ____. - -reverse the polarity of
the induce voltage
When a conductor cuts magnetic lines of force, a voltage
is induced into the conductor. This principle is called
_____ _____. - -electromagnetic induction (the
inductor is the coil of wire).
In electromagnetic induction, increasing the length of the
conductor is normally done by _____. - -adding
more windings (make it bigger)
In a circuit containing resistance and inductance, the time
required for current to reach its full value involves a value
called the _____ time constant. - -R/L
Losses in the core of iron core inductors include _____
and _____ losses. - -Eddy current; Hysteresis
When DC is applied to a coil, a plot of the current flow in
the coil increasing from zero is a(n) _____. - -
exponential curve
Since the direction of movement of a _____ field has been
reversed, the induced voltage is opposite in polarity,
forcing the current to flow in the same direction. - -
collapsing magnetic
The direction of motion is _____, the polarity of the
induced current is reversed and the magnetic field created
by the induced current again opposes the motion of the
magnet. - -reversed
The amount of voltage induced into a conductor moving in
a magnetic field depends on the turns of wire, the _____,
and the speed of cutting action. - -strength of the
magnetic field
Inductance is proportional to the number of _____ of the
wire, the type of core material used, and the cross
sectional area of the core, but inversely proportional to the
core length. - -turns
