单项选择题
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)
A signal derived from a controlled function and returne...
单项选择题A signal derived from a controlled function and returned to the initiating point is called a/an （）.
A.monitoring signal B.inverse signal C.reverse signal D.feedback signal
The purpose of a main switchboard circuit breakers reve...
单项选择题The purpose of a main switchboard circuit breakers reverse-power trip is to （）.
A.prevent main circuit overload B.protect the circuit breaker blowout coil C.prevent alternator motorization D.prevent low voltage tripout
When you are making a high potential test on a piece of...
单项选择题When you are making a high potential test on a piece of repaired electrical machinery, a rise in leakage current indicates （）.
A.good insulation B.bad insulation C.high insulation power factor D.a high slot discharge factor
