深圳市2021-2022学年初三年级中考适应性考试-物理答案(含评分细则)

PAGEPAGE3深圳市2021-2022学年初三年级中考适应性考试物理学科试题参考答案一、单选题（本题共8小题，每题2分，共16分）17.B 18.B 19.D 20.A 21.D 22.C 23.B 24.C二、双选题（有错选不得分、有漏选得2分，本题共5小题，每题3分，共15分）25.BD26.AB27.BD28.AD29.AC三、作图题（本题共2小题，每题2分，共4分）32分）如图所示评分说明：每连对一条导线得1分，导线交叉扣1分。31.（2分）如图所示AAL1L2V评分说明：电源短路0分，只有一盏灯亮得1分。四、实验题（本大题共3小题，每空1分，每图1分，共14分）32.(5分)（1）C（2）如图所示（3）5导体中的电流与导体电阻的乘积一定大于33.（5分）（1）C（2）①0.75 ②实际功率电流没有单位偏大34.（4分）（1）C （2）4 电流 （3）右边容器外的电阻丝断路（或R3断路）或开始左右液面调在同一个水平面上（其它合理答案也给分）五、计算题（共2小题，15分）35.（7分）1（）只闭合1时，电路中只有R工作1U=U=IR=0.3A×40Ω=12V··································································1分1 111 1（2）闭合S、S，R 和R1 1···············································································1分UR12V60I ···············································································1分UR12V6022I=II=I1+I=0.3A+0.2A=0.5A·····················································1分2（（3）电路产生总热量QQ放=WUIt12V0.5A600s3600J·················································1分总（或根据焦耳定律求得总热量，同样给分）Q Q cmt4.2103J/(kg104200J······························1分吸 水因为Q >Q ，所以此电路产生的总热量不能使0.1kg的水温度升高10℃。 1分吸 放（）电源电压12；1 开关S、S都闭合时，通过电流表的电流是0.5A1 UR此电路产生的总热量不能使0.1kg10℃36.（8UR解：1

P 和I

可得：4Ω··························································14Ω··························································1分P额P额

U2 2202 48灯泡电阻：

L 100W WW实t0.64kW0.64kWh10h

0.064kW

······························1分······························1分灯泡实际功率：实由P 和I

UR可得URPR实L64WPR实L64W484L

176V································1分···········································1分R与L串联：U UU 220V································1分···········································1分0 0 L电路电流：IR0

176VURAURA·································································1分41144V11444V114AU0I ·································································1分411（3）总功率：PUI220V A80W ·····················································1411

80%P实P64W80W···························································1分（）灯泡的电阻是48P实P64W80W··········································