What is the difference between a a 90 percent furnace with a sealed combustion system and a typical 90 percent furnace?
A) Sealed combustion units use household vented air for combustion.
B) Sealed combustion units require combustion air to be piped in from the outside.
C) Sealed combustion units do not produce any combustion products.
D) Sealed combustion units may use PVC pipe for venting material.
B
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Colonists objected to the enactment of the Stamp Act in 1765 because
A. it was a very expensive tax. B. they believed it could not be repealed. C. they objected strenuously to the Stamp Act's naked violation of the political principle of "no taxation without representation." D. they opposed all taxes. E. they desired immediate political independence from Great Britain.
When a non-cycling circuit breaker trips open, specifically what prevents the armature from closing when it cools?
A. heat from an integral resistor B. residual heat from the current overload C. pressure from a latching spring D. control coil
Where service entrance conductors extend from the weatherhead, a _______________ is required to keep water from entering the weatherhead and getting into the meter enclosure.
Fill in the blank(s) with the appropriate word(s).
The output voltage of a circuit at 70.7% of its maximum level measured in dB is:
A) 7 dB. B) 3 dB. C) -7 db. D) -3 dB.