学科干货物理电学光的粒子性考点分析2

这周我们继续上周的学科干货话题，对物理第二单元电学和光的粒子性常见考点进行进一步的梳理。下面是%的纯干货，大家做好思想准备哦

1.计算电阻率p

R=pL/A

描述实验：画实验电路图，测什么，画什么，算什么。

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2.串联并联电阻

计算串联并联的电压电流电阻。

3.分压计算。

4.测电源电动势、内阻的实验

画实验电路图。

e.m.f.和p.d.概念

e.m.f：theamountofenergyconvertedintoelectricalenergyperunitchargesupplied

P.D：theamountofelectricalenergyconvertedintootherformsofenergyperunitchargesupplied.

5.半导体

单向导电性。

6.效率efficiency=usefuloutput/totalinput

电功率P=VI

电功W=VIt

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7.光电效应

Workfunction概念：Theminimumenergyrequiredtoremoveoneelectronfromthesurfaceofthemetal.

Thresholdfrequency概念：minimumfrequencyoflightincidentonametalthatwillcauseelectronstobeemittedfromsurface.

Photon概念：quantumofelectromagneticenergy

为何UV能产生光电效应，可见光不能？

1.electronemittedbyabsorptionofphoton.

2.onephotonabsorbedbyoneelectron.

3.ifphotonenergyaboveworkfunctionenergythenelectronemitted

4.photonenergyE=hf,workfunctionφ=hf0

iffrequencyabovethresholdfrequencythenelectronemitted

5.(题目已知该金属的workfunction,可算得)Thresholdfrequency=1.0×Hz

6.visiblelightfrequencyistoolow

为何存在thresholdfrequency？

1.electronemittedbyabsorptionofphoton.

2.onephotonisabsorbedbyoneelectron.

3.thereisaminimumenergyneededforemissionofaelectron

4.PhotonenergygivenbyE=hf,

thresholdfrequencyistheminimumfrequencyfortheemissionofelectrons

为何光电效应支持光的微粒说？

?Increasingtheintensityoflightincreasesthenumberofelectronsemittedpersecond

?Onephotonreleasesoneelectron

?Intensitydeterminesnumberofphotons

OR

?Increasingtheintensityoflightdoesnotincreasethespeedoftheelectrons

?Onephotonreleasesoneelectron

?E=hf,Energyofphotondependsonfrequencynotintensity

OR

?whenfrequencyofincidentlightisbelowthresholdfrequency,noelectronsemitted

?E=hf,Energyofphotonsdependsonfrequency

?Eachphotonneedsaminimumamountofenergy,Wavetheorywouldallowenergytobuildup

OR

?Electronemissionstartsatonce(evenforlowintensity)

?Onephotonreleasesoneelectron

?Wavetheorywouldallowenergytobuildup

是不是感觉信息量满满呢？下期内容我们将继续跟大家分析能级、光谱以及如何观测天体方面的考点，欢迎大家继续







































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