单项选择题
A.change in the impeller diameter B.square of the impeller radius C.cube of the impeller diameter D.impeller efficiency for large changes in its size
Which of the following best describes the thermodynamic...
单项选择题Which of the following best describes the thermodynamic effect on the pressure and volume relationship with regards to saturated gases?（）
A.As pressure decreases, volume increases B.As volume increases, pressure increases C.As volume decreases, pressure decreases D.As pressure increases, volume increases
To operate a centrifugal fire pump at reduced capacity,...
单项选择题To operate a centrifugal fire pump at reduced capacity, you should （）.
A.readjust the relief valve B.throttle the suction line C.throttle the discharge valve D.open the priming line
An AC synchronous transmission type remote steering con...
单项选择题An AC synchronous transmission type remote steering control system consists of a （）.
A.transmitter at the steering station and a receiver at the steering engine B.reversible motor at the steering station geared to the steering pumps C.small induction motor on the bridge which controls the redder through pulleys D.variable displacement hydraulic pump driven by a reversible DC motor
