AND SOLUTIONS GRADED A+
✔✔When some of the generator output is used to supply the field current how is the
generator described? - ✔✔Self-exciting
✔✔When the multimeter is set to amps position the test leads are considered to be in
what state? - ✔✔Short circuit
✔✔What should resistance of an armature be when measured from commutator to
ground with brushes removed? - ✔✔High resistance
✔✔What method of armature winding is used for high current applications? - ✔✔lap
winding
✔✔What should always be done to protect the meter from damage when measuring
unknown voltage? - ✔✔Set to the highest range
✔✔To what scale should the ammeter be set in order to read a current of 2000 ma? -
✔✔10 amp
✔✔What must be done when testing a resistance to avoid readings caused by parallel
circuit paths? - ✔✔Remove one or two of the wire to the item being tested
✔✔0.790 MΩ indicates? - ✔✔790 kΩ
✔✔AC voltage on a voltmeter is always indicated as? - ✔✔RMS
✔✔0 on voltmeter when testing a known power source indicates? - ✔✔Internal fuse is
blown
✔✔.250 MΩ indicates? - ✔✔250,000 MΩ
✔✔What should resistance of a motor or generator commutator be to ground with the
brushes raised? - ✔✔Infinite Resistance
✔✔2230Ω can also be expressed as? - ✔✔2.23 kΩ
✔✔Applied voltage on the primary leads current by? - ✔✔90°
✔✔CEMF can best be described as? - ✔✔Opposes applied voltage
, ✔✔Eddy currents can be described as? - ✔✔Circulating currents set up by magnetic
induction
✔✔a 1:12 fixed voltage transformation ratio transformer is? - ✔✔Step-up
✔✔How would you check for an open primary winding? - ✔✔Measure resistance across
the primary
✔✔If the secondary winding is open what will happen to the secondary resistance? -
✔✔It will be infinity
✔✔When the secondary winding is completely shorted what happens to primary
current? - ✔✔Current is high
✔✔How can you reduce ripple? - ✔✔More coils and commutator segments
✔✔If current carrying wire is placed perpendicular to a field by two magnets of opposite
polarity what happens? - ✔✔Conductor is moved at right angles to the flux from the
magnetic poles
✔✔Inherent current-limiter present for a rotating armature? - ✔✔CEMF
✔✔Elementary AC generator has what that DC doesn't? - ✔✔Split rings
✔✔What provides the connection for the ends of the armature coils to the commutator?
- ✔✔Riser
✔✔Neutral plane is? - ✔✔The point in a coils rotation where zero voltage is induced
✔✔Field that has only a few turns of heavy wire? - ✔✔Series
✔✔Armature reaction can be compensated for by using? - ✔✔Interpoole windings
✔✔What are two circuits of a separately-excited generator called? - ✔✔The field and
armature circuit
✔✔In a DC series generator current flows only when? - ✔✔There is a load
✔✔An elevator that travels faster in the up direction when it is fully loaded that it does
when it is empty is _________-compounded - ✔✔Over
✔✔A shunt generators output drops as load is? - ✔✔Increased