【简答题】如图所示的电路,R=4Ω,另一个电阻Rx和电源电压U未知,当闭合开关 S 2 , 而 S 1 、S 3 断开时,电流表的示数为0.5A;如果断开 S 2 ,闭合开关 S 1 、S 3 时,电流示数为2.25A。 求:电阻Rx的阻值。
【简答题】整 流 滤 波 电 路 如 图 5 所 示,二 极 管 是 理 想 元 件 , 变压器副边电压有效值 U 2 =10V , 求: (1) 开 关 S1 闭 合、S2 断 开时, 直 流 电流表的 读 数 : (2) 开关 S1 断 开、S2 闭 合 时, 直 流 电压表的 读 数 : (3) 开 关 S1 、S2 均 闭 合 时, 直 流 电压表的 读 数 :
【单选题】有一碱样品,可能是 NaOH 或 Na 2 CO 3 或 NaHCO 3 或它们的混合物。若用 HCl 滴定液清定至酚酞变色时消耗滴定液 V 1 ml ,滴定至甲基橙变色时又消耗滴定液 V 2 ml ,若 V 1 > V 2 ,则的组成是 ( )
【简答题】FDI has grown more rapidly for several reasons. First, business firms still fear _______________ pressure. Second, the increase in FDI is being driven by the political and _______________ changes in m...
【判断题】叠加定理只适用于线性电路的电压和电流的计算,不适用于非线性电路,也不适用于线性电路的功率计算。
【单选题】导游服务是导游人员通过向游客提供劳务而创造特殊( )的劳动。
【单选题】If a business and its competitor has the same “S” and the same cost of the first unit ,the business should .如果某企业与其竞争对手具有相同的初始单位产品成本和相同的学习率,则该企业应该
A.
Improving Personnel learning & Supervisory learning 提升个人学习能力和监督学习的工作
B.
Finding better processes and being faster to implement them 找到更好的业务流程并先于对手实施
C.
Starting production behind its competitors 晚于对手生产
D.
Starting production ahead of its competitors 先于对手生产
【单选题】Many of the early U.S. railroad companies defined themselves as being in the railroad business instead of being in the transportation needs business. These companies used ______________.
A.
resource-based missions
B.
customer-oriented missions
C.
product-oriented missions
【单选题】If the early U.S. railroad companies defined themselves as being in the transportation needs business, which is more customer-oriented, they might have successfully moved into what product/service bef...
A.
Commercial aviation (such as Delta and United)
B.
Modern shipping and logistics (such as FedEx and UPS)
C.
International cargo containers on large ocean ships
D.
Fuel efficient automobiles (such as Toyota and Ford)