题目

Jessie feels excited b 【小题1】   it is her first day to work at Mr. Smith's shop. After breakfast she w 【小题2】  a pair of new shoes. She says g 【小题3】   to her mother and goes out of the house. The shop is n 【小题4】   her home so she walks there. There is a heavy r 【小题5】   the night before and there is dirty water all over the street. W  【小题6】  she goes across the street, a car runs p 【小题7】  her and splashes（溅起）water on her. Her shoes g 【小题8】   dirty. Luckily, it is hot. She is very sad and she want某导体两端的电压为9伏，10秒内通过该导体横截面积的电荷量为6库，通过该导体的电流为________ 安，这段时间内电流做功为________ 焦；若将该导体两端的电压调整为12伏，其电阻为________ 欧。 0.6 54 15 【解析】通过导体的电流：I＝＝0.6A，这段时间内电流做功：W＝UIt＝UQ＝9V×6C＝54J，由I＝可得，导体的电阻：R＝＝15Ω，因电阻是导体本身的一种性质，与导体两端的电压和通过的电流无关，所以，将该导体两端的电压调整为12伏时，导体的电阻仍为15Ω不变。