单项选择题
A.heat-resisting acrylic B.heat-resisting aluminum C.insulating varnish D.insulating white lead
The electrolyte in a lead-acid storage battery consists...
单项选择题The electrolyte in a lead-acid storage battery consists of distilled water and （）.
A.hydrogen chloride B.calcium chloride C.sulfuric acid D.muriatic acid
A circuit breaker and a fuse have a basic similarity in...
单项选择题A circuit breaker and a fuse have a basic similarity in that they both （）.
A.can be reset to energize the circuit B.should open the circuit when overloaded C.will burn out when an over current flow develops D.All of the above
An electrical device which prevents an action from occu...
单项选择题An electrical device which prevents an action from occurring until all other required conditions are met is called a/an （）.
A.limit B.monitor C.modulator D.interlock
