挑战习题
1/5单选题
难度:

1.小明通过实验研究电阻大小与哪些因素有关,他找到四根金属线如图所示,图中A为锰铜线,B、C、D为镍铬合金线,S表示横截面积。在研究电阻的大小与导体材料的关系时,他选择了其中两根金属导线分别进行实验比较,应选择()
A A和B
B A和D
C B和C
D B和D
提示1:
5o6n5Yi25Y+Y6YeP5rOV
正确答案:QQ==
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