【单选题】电阻元件的伏安特性曲线反映了电阻元件的导电特性。A、B两个导体的伏安特性曲线如下图所示,其中图线A与横轴成 角。关于这两个导体的伏安特性曲线的下列说法不正确的是( )。
B.
导体B是非线性元件,曲线上某点切线的斜率为相应状态的电阻的倒数。
C.
两条图线相交的点表示两电阻元件在此状态时的I、U、R均相等。
【简答题】按照加工原理不同分类,常用的齿轮切削加工方法有成形法(仿形法)和 两种。
【单选题】Which of the following is right?
A.
We don't need to learn any foreign languages.
B.
We can do well in all our work without English.
C.
We should learn English because we need to face the world.
【单选题】If there is not any help , we can’t do it.
D.
Whether there is not any help
【简答题】图2-5中,已知u s =10V、i 1 =2A、R 1 =4Ω、R 2 =1Ω,求i 2 。
【单选题】We can't do any more now. Let's call it a ______.