设某工厂变电所380V侧母线上接有380V感应电动机250kW,平均cosφ=0.7

题型:问答题 案例分析题

问题:

设某工厂变电所380V侧母线上接有380V感应电动机250kW,平均cosφ=0.7,效率ηn=0.75。该母线采用LMY一100×10的硬铝母线,水平平放,档距为900mm,档数大于2,相邻两相母线的轴间距离为160mm。试求该母线三相短路时所受的最大电动力,并校验其动稳定性。

考点:电气工程师(供配电)35kV及以下导体、电缆及架空线路的设计选择35kV及以下导体、电缆及架空线路的设计选择题库
题型:问答题 案例分析题

铁心插入通电螺线管,铁心被______,产生了______,于是通电螺线管周围既有______产生的磁场,又有______产生的磁场,使磁场大大增强.

题型:问答题 案例分析题

现行财务制度规定,施工企业计提折旧一般采用()。

A.平均年限法

B.双倍余额递减法

C.年数总和法

D.加速折旧法

题型:问答题 案例分析题

Americans’ (1) impulses keep generating surprises. Charitable giving plays an even larger role in the (2) . Demand for nonprofit services gets proportionately bigger as a locality’s (3) rises. The philanthropy of the wealthy may not hinge on tax (4) to the degree many believe. The US (5) the world in levels of charitable activity. Some experts see charity as a (6) trait of the US, more than (7) or business. But those forces may be (8) , as many nonprofits, from healthcare to classical music are selling (9) in a marketplace alongside for-profit (10) . Charity is no mere (11) activity. It pays off for society in ways that may (12) the rates of return on many traditional investments. Charity not only helps those on the (13) end but also strengthens the (14) of society at large. Moreover, it appears to make the givers themselves more (15) . The pattern that conservatives are better givers than (16) is less about politics than about charity-linked (17) most common to conservatives, religious commitment, marriage and children, and entrepreneurship. The main point is that more Americans, regardless of ideology, embrace giving as a tool for (18) . The urge to make a difference, and to take (19) in it, outweighs (20) considerations.

题型:问答题 案例分析题

下列属于公安消防部队大队党的基层委员会学习工作生活制度的是()。

A.党课制度

B.党员汇报制度

C.重大决策征求意见制度

D.中心组理论学习制度

题型:问答题 案例分析题

漂白粉是水产养殖常用的药物,测定其质量主要测的指标是()。

A.钙的含量

B.氧的含量

C.水的含量

D.有效氯含量

更多题库