试题与答案

用功率P0＝3的光源，照射离光源r=5m处的某块金属的薄片. 已知光源发出的是波

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题型：填空题

题目：

用功率P0＝3的光源，照射离光源r=5m处的某块金属的薄片. 已知光源发出的是波长＝663nm的单色光，普朗克常量h=6.63×10-34J.s.

(1)1s内该金属板1m2面积上接受的光能为_____J.

(2)1s内打到金属板1m2面积上的光子数为________.

答案：

0.03 ，

题目分析：该光源1s内发出的能量为，照射面积为，所以单位面积上接受的能量为,

每个光子的能量为

故1s内打到金属板1m2面积上的光子数为

点评：做本题的关键是知道照射面积为

考点：光电效应方程
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题型：阅读理解

阅读短文，回答问题。 

       Hi, Jack, we're going to have our school sports meeting on the playground next week. It will last three days

from Thursday to Saturday. We have many competitions in running, such as 100-meter race, 400-meter race 

and the relay race. We also have the long jump, the high jump, and so on. I know you're good at running. Would

you please take part in the boy's 400-meter relay race which starts at 10:30 am on Friday? Please be on time, 

wear your sports shoes and take a bottle of water.           

       Good luck to you!               

                                                                                                                                               Yours,

                                                                                                                                               Jim        

1. What does Jim ask Jack to do and why?  

                                                                          

2. When does the boy's 400-meter relay race begin? 

                                                                          

3. How long does the sports meeting last?

                                                                         

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题型：单项选择题

The Lake District in north-west England is an area remarkably little affected by industrialization. The principal activity is still sheep-farming, as it has been for a thousand years, and many ancient words like "fell" for "hill" and "tam" for "lake" are still in daily use. In spite of its heavy rainfall and relative inaccessibility, its special atmosphere and spectacular natural beauty combine to make this one of England’s favourite holiday areas at all seasons of the year. But at Christmas 1968, still gripped by the fear that foot-and-mouth disease could spread to the hill flocks and sweep like wildfire right up to the Scottish border, it was quieter than ever before in this century. Luckily not a single farm had caught tile infection, the nearest case having been an isolated one at Kendal several weeks before. But every Lakeland farmer knows that one case among the unfenced hill flocks on the fells could lead to complete annihilation of hundreds of thousands of sheep and the virtual end of the district’s principal industry; you cannot replace sheep, acclimatized to their own part of the fell for generations, in the same way that you can replace cattle in a field.
Nobody could remember a Christmas like it, especially Boxing Dab, which is traditionally one of the big outdoor holidays of the Lakeland year. Normally this is a day spent following the mountain packs of hounds, fell-walking and, if the weather is propitious, skiing and skating, but this time there were none of these things. Visitors were actively discouraged, and those who did come were asked not to go on the fells, footpaths or bridleways or near farmland, while motorists were requested not to drive on minor roads and to shun the smaller valleys. The enterprising hotels which had earlier in the year decided to keep open during the winter were by the end of October having a desperate time. Hundreds of bookings had been cancelled and scores of dinner parties and young farmers’ reunions eliminated. All youth hostels were closed. At least one climbing club, unable to climb, substituted a training programme of films and simulated climbs on the more substantial municipal buildings.
The weather in the area was dry, crisp, windless and cold, in fact ideal for brisk outdoor activities. But nobody was able to enjoy it. Everything was stopped: hunting, walking, climbing, skiing, motor cycle trials, sporting events of every description. All the seasonal dances, festivals, conferences, shepherds’ meets and a hundred and one, other social occasions abandoned. The ice was bearing on some of the lakes but you could not go skating there. Meanwhile the foxes, emboldened by an unprecedented freedom from harassment, were stalking closer to the farms and the flocks of Christmas turkeys, while the hounds sulked miserably in their kennels.
Farmers are apt to criticize some sections of the outdoor fraternity for their occasional thoughtless behaviour, but the way that walkers, climbers, skiers, fishermen, hunters and the rest went out of their way to help them at this time should never be forgotten. The general public, locals and visitors alike, tried to give the fell farmers a sporting chance, and this remarkable display of public spirit was the one bright note in a very sad time.

Why were some hotels described as "enterprising"

A．(A) Because hundreds of bookings had been cancelled.

B．(B) Because they decided to keep open during the winter.

C．(C) Because they still held dinner parties and young farmers’ reunions.

D．(D) Because they substituted a training programme of films and simulated climbs.
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