單項選擇題

Which of the listed sections of an emergency switchboard is used to supply power for alarm signals under emergency conditions?（）

A.The generator and bus transfer section
B.The 450 volt, 60 cycle, 3 phase bus
C.The 120 volt, 3 phase, 60 cycle bus
D.The 24 volt DC bus

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單項選擇題

When the current in a power transmission line is increased, the power loss （）

A.increases as the square of the current
B.decreases as the square root of the current
C.remains the same, as it is independent of current flow
D.increases in direct proportion as the current

單項選擇題

An operational amplifier, as used in todays consoles, may have a calculated gain of 5√This means that as the input changes by （）

A.1 volt, the output changes 5 volts
B.5 volts, the output changes 1 volt
C.5 volts, the output changes 10 volts
D.10 volts, the output changes 5 volts