单项选择题
A.diode B.transformer C.transistor D.rheostat
Which of the listed devices is used to measure pressure...
单项选择题Which of the listed devices is used to measure pressure and convert it to an electrical signal?（）
A.Transducer B.Reducer C.Transformer D.Rectifier
A direct current passing through a wire coiled around a...
单项选择题A direct current passing through a wire coiled around a soft iron core is the description of a simple（）.
A.magnetic shield B.electromagnet C.piezoelectric device D.electromagnetic domain
Which of the following electric motors would be the saf...
单项选择题Which of the following electric motors would be the safest and most reliable to use on the main deck of a vessel in foul weather conditions?（）
A.Sealed motors B.Drip proof motors C.Enclosed motors D.Watertight motors
