单项选择题
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
The sub-multiple prefix "milli" (m) means （）.A.one thou...
单项选择题The sub-multiple prefix "milli" (m) means （）.
A.one thousandth (10 to the -3rd power) B.one millionth ( 10 to the -6th power) C.one billionth ( 10 to the -9th power) D.one trillionth (10 to the -12th power)
A “dead front” switchboard is one （）.A.without switches...
单项选择题A “dead front” switchboard is one （）.
A.without switches on it B.with insulated switches and no exposed terminals C.without circuit breakers D.without safety hand nails nor rubber mats
