What advantage is there to maintaining a negative pressure on the heat exchanger?
A) The negative pressure helps draw in return air from the house, increasing efficiency.
B) Combustion air can only be drawn into the oil burner if a negative pressure is maintained.
C) The vent will not work unless the heat exchanger is at a negative pressure.
D) Safety; it ensures combustion products do not leak out into the air stream.
D
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The inactive winding must be open circuited to ____circulating current due to transformer action between the idle winding and the energized winding.
a. reduce b. prevent c. monitor d. promote
Using Fig. 3.88, design a problem to help students better understand mesh analysis using matrices.
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What is the purpose of crossing the tip and ring wires over each other to form a twisted pair?
A) to produce a canceling effect of the signals and thus eliminate cross talk B) to block electromagnetic interference from outside influences such as fluorescent lights C) both a and b are true D) neither a nor b is true
When an electron breaks away from its covalent bond, the space previously occupied by the electron is referred to as a(n) ____________________.
Fill in the blank(s) with the appropriate word(s).