【单选题】【消耗次数：1】
离心泵铭牌上标明的扬程m可理解为 。
①
A、该泵在规定转速下可以将20℃的水升扬的高度
②
B、该泵在规定转速、最高效率下将20℃的水升扬的高度
③
C、该泵在规定转速下对20℃的水提供的压头
④
D、该泵在规定转速、最高效率下对20℃的水提供的压头
参考答案：
复制
纠错
相关题目
【单选题】
将一水池中20℃的水用泵输送到一敞口高位槽中，两液面之间的垂直距离为20m，泵的吸入口在水池液面上方2 m处。在某送液量下， 泵对水作功219.6J/kg，管内摩擦系数λ为0.018，吸入管路总长为40 m，压出管路总长为70m（两长度包括全部局部阻力的当量长度在内），输水管尺寸为Ф108 ×4mm，泵的效率为70%。已知20℃水的密度为1000kg/m3试求：（1）输水量，m3/h 。（2）泵的轴功率。
①
Q=43.52m^3/hN=9.45Kw
②
Q=53.72m^3/hN=3.79Kw
③
Q=43.52m^3/hN=3.79Kw
④
Q=53.72m^3/hN=9.45Kw
【单选题】
在某单泵输液的管路中，并联一台同一型号的离心泵，单泵与并联双泵的输液效果为————。
①
并联的输液量将是单泵的两倍
②
并联的扬程将是单泵的两倍
③
并联的能耗将是单泵的两倍
④
并联的输液量、扬程或能耗都不会是单泵的两倍
【单选题】
倘若开大离心泵出口阀门，提高泵的输液量，会引起 。
①
A、泵的效率提高
②
B、泵的效率降低
③
C、泵的效率可能提高也可能降低
④
D、泵的效率只决定于泵的结构及泵的转速，与流量变化无关
随机题目
【单选题】
The donated liver came from the UK, but the hospital is giving no further __________ .
①
instance
②
character
③
items
④
details
【单选题】
Well, it’s getting late. I must be going. Thank you again for inviting me to the party.
①
Oh, it’s so late
②
Thank you for coming
③
Oh, so soon?
④
I really had a happy time
【单选题】
I won’t be able to attend the meeting tonight because _________ .
①
I must teach a class
②
I teach a class
③
I will be teaching a class
④
I will have been teaching a class
【单选题】
Excuse me, but can you tell me the way to the airport?
①
Don’t ask that
②
Sorry, I’m a stranger here
③
No, I can’t say that
④
No, you’re driving too fast
【单选题】
These two areas are similar __________ they both have a high rainfall during this season.
①
to that
②
besides that
③
in that
④
except that
【单选题】
Success results ___________ hard work, and hard work results in success.
①
from
②
in
③
by
④
with
【单选题】
David, there a dictionary and some books on your desk. Please put them away.
①
is
②
are
③
have
④
has
【单选题】
_________ is no reason for dismissing him.
①
Because he was a few minutes late
②
Owing to a few minutes being late
③
The fact that he was a few minutes late
④
Being a few minutes late
【单选题】
Police are __________ the disappearance of two children.
①
looking out
②
looking after
③
looking into
④
looking on