The （）, cage rotor induction motor is the first choice marine motor in most modern ships because of its electrical and mechanical simplicity.

The operation of paralleling two alternators requires t...

单项选择题The operation of paralleling two alternators requires the voltages to be （）and also in phase.

The （） is a measure of the phase difference between vol...

单项选择题The （） is a measure of the phase difference between voltage and current and is expected as the cosine of phase angle.

The overcurrent relay （） the motor contactor when the m...

单项选择题The overcurrent relay （） the motor contactor when the motor exceeds its rated current.