问题
选择题
They would tell how the slaves _____ on a ship to an American port on a rainy day. |
A. being brought B. could have brought C. had been brought D. was to be brought |
答案
答案:C
They would tell how the slaves _____ on a ship to an American port on a rainy day. |
A. being brought B. could have brought C. had been brought D. was to be brought |
答案:C
(1)以下四个中学学生实验中都要用到小球或者重锤,实验中需要测定小球或重锤质量的是______.(选填下面正确选项前的代号字母)
A.验证机械能守恒定律
B.用单摆测定重力加速度
C.验证动量守恒定律
D.研究平抛物体的运动
(2)一个小灯泡的额定电压为6.3V,额定电流约为0.3A,用以下所给的实验器材描绘出小灯泡的伏安特性曲线.实验电路如图1所示.
电源E1:电动势为8.0V,内阻不计;
电源E2:电动势为12.0V,内阻不计;
电压表V:量程为0~10V,内阻约为10kΩ;
电流表A1:量程为0~3A,内阻约为0.1Ω;
电流表A2:量程为0~300mA,内阻约为1.0Ω;
滑动变阻器R:最大阻值10Ω,额定电流1.0A;
开关S,导线若干.
①依照实验电路图将图2中的实物图连接成实验电路.
②实验中电源应该选用______;电流表应该选用______.
③实验测出的数据如下表所示,依照这些数据在图3所示的坐标中描绘出该小灯泡的伏安特性曲线.
U/V | 0 | 0.5 | 0.8 | 1.0 | 1.2 | 1.5 | 2.0 | 2.5 | 3.0 | 4.0 | 5.0 | 6.0 | 6.2 |
I/A | 0 | 0.05 | 0.08 | 0.10 | 0.12 | 0.14 | 0.16 | 0.18 | 0.20 | 0.23 | 0.25 | 0.27 | 0.27 |