单项选择题
A.over-speed trip B.reverse power relay C.back pressure trip D.governor controls
Which of the electrical properties listed will always b...
单项选择题Which of the electrical properties listed will always be the same for each component in a parallel circuit?（）
A.Impedance B.Current C.Resistance D.Voltage
A switchboard, for a AC electrical distribution system,...
单项选择题A switchboard, for a AC electrical distribution system, will be provided with which of the following components （）.
A.Frequency meter B.Ammeter C.Voltmeter D.All of the above
The sub-multiple prefix “nano” (n) means （）.A.thousandt...
单项选择题The sub-multiple prefix “nano” (n) means （）.
A.thousandth (10 to the-3rd power) B.millionth (10 to the-6th power) C.billionth (10 to the-9th power) D.trillionth (10 to the-12th power)
