衡量汽轮机内能量转换完善程度的指标,为蒸汽在汽轮机中的()与汽轮机的()之比。
参考答案:理想焓降;有效焓降
(2013·济南市三模)One evening Harry phoned me, ________ me to come to his flat as soon as possible.
A.asked
B.having asked
C.asking
D.being asked
小灯泡L的额定电压为6V,小明通过实验测得其电流随电压变化的曲线如图所示。由图可知,当小灯泡L正常发光时,通过其灯丝的电流是 A;通过调节滑动变阻器,使小灯泡两端的电压为3V,则此时小灯泡L消耗的实际功率为 W。