挑战习题
1
/5
单选题
难度:
1.旧白炽灯在工作时,容易在灯丝最细处熔断,这是因为与相同长度的较粗灯丝相比,灯丝最细处( )
A
功率最大
B
电流最大
C
电阻最小
D
电压最小
提示1:
54Gv5Lid5pyA57uG55qE5Zyw5pa555S16Zi76L6D5aSn77yM5Zyo5Liy6IGU55S16Lev5Lit77yM55S16Zi76LaK5aSn77yM55u45ZCM5pe26Ze05YaF5Lqn55Sf55qE54Ot6YeP6LaK5aSa
正确答案:
QQ==
55S16Zi75LiO5qiq5oiq6Z2i56ev55qE57KX57uG5pyJ5YWz77yM5b2T6ZW/5bqm55u4562J77yM5p2Q5paZ55u45ZCM5pe277yM5qiq5oiq6Z2i56ev5bCP5pe277yM55S16Zi75aSn77yM5Zyo5ZCM5LiA5qC554Gv5Lid5Lit77yM5aSE5aSE55S15rWB55u4562J77yM5pe26Ze055u4562J77yM55Sx5a+85L2T5Y+R54Ot5YWs5byPUT1JPHN1cD4yPC9zdXA+UnTnn6XvvIznu4blpITnmoTnlLXpmLvlpKfvvIzlj5Hng63lpJrvvIzlip/njoflpKfvvI7mlYXpgIlB77yO
2
/5
单选题
难度:
2.电流热效应在科研、生产、生活中被广泛应用,但有时它也会给我们带来危害,下列情况不属于防止电热危害的是()
A
电视机的后盖有许多孔
B
电动机外壳有许多散热片
C
家电长时间停用,隔一段时间应通电一次
D
电脑机箱内有小风扇
提示1:
5pWj54Ot5piv5Li65LqG6Ziy5q2i55S154Ot5bim5p2l55qE5Y2x5a6z
正确答案:
Qw==
5a6255S16ZW/5pe26Ze05YGc55So77yM6ZqU5LiA5q615pe26Ze05bqU6YCa55S15LiA5qyh5LiO55S154Ot5peg5YWz77yM5pWF6YCJQy4=
3
/5
单选题
难度:
3.某长度为a的均匀导线接在电源上.每分钟产生的热量为Q.把这段导体对折后仍接在这个电源上,则每分钟产生的热量是( )
A
2Q
B
4Q
C
Q /2
D
Q /4
提示1:
5a+85L2T5a+55oqY5ZCO5LuN5o6l5Zyo6L+Z5Liq55S15rqQ5LiK77yM6ZW/5bqm5YeP5Y2K77yM5qiq5oiq6Z2i56ev5ZCM5pe25aKe5aSn5LiA5YCN77yM55S16Zi75Li65Y6f5p2l55qEPGltZyB3aWR0aD0xNyBoZWlnaHQ9NDIgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC83My8yNC9yQkFDRTFUSW96ekJUR1RnQUFBQkw4T1JtTTA3ODAucG5nIj4=
正确答案:
Qg==
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
4
/5
单选题
难度:
4.
如图所示电路中,已知R
1
>R
2
,把他们分别接在电压为U的电源两端,在相同的时间内四个电路中总共放出的热量由多到少的顺序是( )
A
甲、乙、丙、丁
B
甲、丙、丁、乙
C
丙、丁、乙、甲
D
乙、丁、丙、甲
提示1:
PHA+5b2T55S15rqQ55S15Y6L5ZKM6YCa55S15pe26Ze055u45ZCM5pe277yM55S16Zi76LaK5aSn55qE55So55S15Zmo77yM5Lqn55Sf55qE54Ot6YeP6LaK5bCPPC9wPg==
提示2:
PHA+5bm26IGU55S16Lev5Lit77yM562J5pWI55S16Zi75bCP5LqO5Lu75L2V5LiA5Liq55S16Zi7PC9wPg==
正确答案:
RA==
PHA+5Zug5Li655Sy44CB5LmZ44CB5LiZ44CB5LiB5Zub5Liq55S16Lev5Lik56uv55S15Y6L55u4562J77yM55S16Zi75YWz57O75Li6UjxzdWI+55SyPC9zdWI+77yeUjxzdWI+5LiZPC9zdWI+77yeUjxzdWI+5LiBPC9zdWI+77yeUjxzdWI+5LmZPC9zdWI+77yM5qC55o2u57qv55S16Zi755S16Lev54Sm6ICz5a6a5b6L5YWs5byPUT1VPHN1cD4yPC9zdXA+IHQvUuefpe+8jOebuOWQjOaXtumXtOWGheS6p+eUn+eahOeDremHj+WFs+ezu+S4ulE8c3ViPuS5mTwvc3ViPu+8nlE8c3ViPuS4gTwvc3ViPu+8nlE8c3ViPuS4mTwvc3ViPu+8nlE8c3ViPueUsjwvc3ViPu+8jOaVhemAiUQuPC9wPg==
5
/5
单选题
难度:
5.两根阻值相同的电阻丝,先串联后并联,分别接入同一个电源,若消耗的总电能相同,则两种方法所需要的时间之比是( )
A
1:2
B
2:1
C
1:4
D
4:1
提示1:
5Lik5Liq55S16Lev55qE5oC755S15Y6L55u4562J77yM5Yip55So5YWs5byPUT1VPHN1cD4yPC9zdXA+dC9S5rGC6Kej5Zyo5Lik56eN5oOF5Ya15LiL5Lqn55Sf55u45ZCM54Ot6YeP5omA6ZyA6KaB55qE5pe26Ze05LmL5q+U
正确答案:
RA==
6K6+5q+P5Liq55S16Zi755qE6Zi75YC85Li6Uu+8jOWImeS4pOS4queUtemYu+S4suiBlOWQjueahOaAu+eUtemYu++8mlI8c3ViPjE8L3N1Yj49MlLvvIw8YnI+5bm26IGU5ZCO55qE5oC755S16Zi777yaUjxzdWI+Mjwvc3ViPj1SLzLvvIzlm6DnlLXmupDnlLXljovkuI3lj5jlkoxRPHN1Yj4xPC9zdWI+PVE8c3ViPjI8L3N1Yj7vvIzmiYDku6XnlLFRPVU8c3VwPjI8L3N1cD50L1Llj6/nn6XvvJp0PHN1Yj4xPC9zdWI+77yadDxzdWI+Mjwvc3ViPj0077yaMe+8juaVhemAiUTvvI4=