某同学在做测定小灯泡功率的实验中得到如下一组U和I的数据:
0 33598 33606 33612 33616 33622 33624 33628 33634 33636 33642 33648 33652 33654 33658 33664 33666 33672 33676 33678 33682 33684 33688 33690 33692 33693 33694 33696 33697 33698 33700 33702 33706 33708 33712 33714 33718 33724 33726 33732 33736 33738 33742 33748 33754 33756 33762 33766 33768 33774 33778 33784 33792 176998
编号 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
U/V | 0.20 | 0.60 | 1.00 | 1.40 | 1.80 | 2.20 | 2.60 | 3.00 |
I/A | 0.020 | 0.060 | 0.100 | 0.140 | 0.170 | 0.190 | 0.200 | 0.205 |
(1)在图中画出I-U图线.
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(2)从图线上可以看出,当功率逐渐增大时,灯丝电阻的变化情况是____________________.
(3)这表明导体的电阻随温度升高而________________.