A.magnetic shield
B.electromagnet
C.piezoelectric device
D.electromagnetic domain
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A.Sealed motors
B.Drip proof motors
C.Enclosed motors
D.Watertight motors
A.both meters in series with the resistance
B.both meters in parallel with the resistance
C.the ammeter in series and the voltmeter in parallel with the resistance
D.the ammeter in parallel and the voltmeter in series with the resistance
A.open circuit
B.short circuit
C.polarized ground
D.ground reference point
A.Contactors control current and relays control voltage
B.A relay is series connected and a contactor is parallel connected
C.Contactors can handle heavier loads than relays
D.Contactors are made from silver and relays are made from copper
A.short proof
B.ground proof
C.explosion proof
D.overload proof
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