12.
The action that will NOT aid in making an electromagnet more powerful
is
a.
winding more turns on the coil.
b.
increasing the amount of current flow.
c.
reversing the direction of current flow.
d.
substituting a different type of coil material.
13.
The most practical
means
of
increasing
the
output
voltage
of
a
generator is to increase the
a.
field strength by passing more current through the field windings.
b.
diameter of wire in the armature coil.
c.
resistance of wire in the field coils.
d.
number of field poles.
14.
A loop or single turn of wire on the armature of an ac generator
produces a continuously changing voltage during its rotation in the magnetic field.
Maximum voltage is produced when the loop sides are
a.
cutting a maximum number of flux lines.
b.
moving parallel to the direction of the field.
c.
standing still at a position of maximum magnetic flux.
d.
standing still at a position of minimum magnetic flux.
15.
The property that enables a coil to develop an opposing voltage is
a.
counter EMF.
c.
transformer action.
b.
self-inductance.
d.
inductive reactance.
16.
The phase
relationship
of
current
and
voltage
when
applied
to
an
inductor is that the
a.
applied voltage leads the current.
b.
current leads the applied voltage.
c.
current and applied voltage are in phase.
d.
current and applied voltage are 180 degrees out of phase.
308
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