单项选择题
A.inductance B.capacitance C.resistance D.amperage
Which of the motors for the devices listed below is fit...
单项选择题Which of the motors for the devices listed below is fitted with an instantaneous overload relay?（）
A.Fan B.Pump C.Winch D.Machine tool
One factor that determines the frequency of an alternat...
单项选择题One factor that determines the frequency of an alternator is the（）.
A.number of turns of wire in the armature coil B.number of magnetic poles C.strength of the magnets used D.output voltage
The device that most commonly utilizes the principle of...
单项选择题The device that most commonly utilizes the principle of electromagnetic induction is the（）.
A.diode B.transformer C.transistor D.rheostat
