本區搜索:
Yahoo!字典
打印

[問題] Phy mc一問 (light wave)

[隱藏]

Phy mc一問 (light wave)

1974ce

A parallel beam of rays after passing through a converging lens L converges to a point F. If the lens is now completely surrounded by a clear liquid having the same refractive index as the lens, you would expect the beam to
A. converge to the point X
B. converge to the point F
c. converge to the point Y
d. emerge as a parallel beam
ANS:C
點解唔係D

AL1981#19
The image of an object formed on a screen by a thin converging lens has a height a. By moving the lens towards the screen, a second lens position is found at which the height of the image formed on the screen is b. What is the height of the object?
a. 1/2(a+b)
b. 1/2(ab)^(1/2)
c.(ab)^(1/2)
d.(a^3/b)^(1/2)
ANS: C

唔識做 thanks各位幫幫手

[ 本帖最後由 karacyyu 於 2012-8-2 05:54 PM 編輯 ]
附件: 您所在的用戶組無法下載或查看附件
   

TOP

回覆 1# karacyyu 的帖子

1.  無圖無真相

2. 設第1次的 lens-to-object distance 做x  ,lens-to-screen distance 做y
object 的高做M
第1次︰x / y  = a / M
第2次︰x, y 交換(光的可逆性)
y / x = b / M

2式兩相乘,易得︰M=(ab)^0.5
路曼曼其脩遠兮 吾將上下而求索

TOP

重要聲明:小卒資訊論壇 是一個公開的學術交流及分享平台。 論壇內所有檔案及內容 都只可作學術交流之用,絕不能用商業用途。 所有會員均須對自己所發表的言論而引起的法律責任負責(包括上傳檔案或連結), 本壇並不擔保該等資料之準確性及可靠性,且概不會就因有關資料之任何不確或遺漏而引致之任何損失或 損害承擔任何責任(不論是否與侵權行為、訂立契約或其他方面有關 ) 。