电压就是电场力将电荷从一点移动到另一点()与该电荷电量的比值。
A、所加的力
B、所做的功
C、所走的路径
D、所用的时间
参考答案:B
阅读短文,回答下列问题。
It's Saturday morning. Mrs Edwards opens the window and looks outside. She is very happy. "It's going to
be a beautiful day!" She wakes up her small son at seven and says, "Get up, Teddy. We are going to the zoo
today. Wash your hands and face and have your breakfast quickly. We are going to New York by car."
Teddy is six years old. He is very happy. He gets up and washes his hands and face quickly. "Mum, let's
go." "But your breakfast?" "I can have it in New York. Let's go."
1. What day is it today?
2. What's the weather like today?
3. Where will they go?
4. What should Teddy do after he gets up?
传感器是能将感受到的物理量(如力、热、光、声等)转换成便于测量量(一般是电学量)的一种元件,在自动控制中有相当广泛的应用,如图所示的装置是一种测定液面高度的电容式传感器,金属芯线与导电液体构成一个电容器,从电容C大小的变化情况就能反应出液面高度h的高低情况,则二者的关系是( )
A.C增大表示h减小
B.C增大表示h增大
C.C减小表示h增大
D.C的变化与h变化无关