1967-04-20 — Page 17

CITY HALL

育效僑部

筤餃

日一十月三年未丁胶寛

WAH KIU YAT PO

姐

短檵

中文 ▶ 考試題預習專欄|

.

尹國龍院擬,懷知

物理科 (廿五)

。鄧炳恩。

3. 電場、電流及歐姆定律問答計算題題解

後間工

1. 解: OA = c.0 =OR

A (-8) N

B(+10)

保新湯

片刷元幣 式搬

= pu=5JZ CL

(a)FFAFE

天道之跳衣

下月宄日開課

本月廿五日前須報名

·木機器之正確使用,安全撒施,及保搽发

綠舞提蘇官小雕, 精

清变九一校舞伯舞

玷鄒立子午

北

`一保校

小興校

110cm

英文中學會考試題預習專欄

←

(STZ)

(5F)

FB Di+4)

生物科

=0.04 dyres

$.5.5an dhu

(廿五)

BIOLOGY (25)

山度士 •

(日.Sc.Din.Ed)

E = Fe - Fo

10.

= 0.12 dyne's......

(5F) 10.042.+0.122

=0.13_dynes

F

= 0.13 . s. 40

1

(b)

V.

(-8). AO

(-6)

(+4)

+

门

=0

V1 = (-3)

+

(+10) RO

(+10) (-6)

+

+

AM

BM

~M

(+4) DM

+ 0.22

W

Q (Vm ~ Vo) = 4 (0.X<~0)

1

+

2. 解:在用葱斯登電橋原理在曾驗室

中湨電阻真裝置如下圈称為滑尺 橘電路中尺曷可變電阻 ab

米之均匀電阻線、R、為欲測定: 電阻,R.為電阻箱,可讀出電阻之 数目(過電流計,一端連接於 C另一端連接電筆 以使在電阻 總上滑動,通電流後,滑動電 直至@之指針為零記錄,见及 長度則

Bu

R2

4.1.Give an Ent to show STOMATAL" TRANSPIRATION

EXPERIMENT TO SHOW STOMATAL TRANSPIRATION

TaA CONTROL EXPERIMENT: Take four larga leaves of

equal size and prepare them as instructed belaut

{1}}

(11) (ili

(iv) (v).

Cover the upper and Lower surfaces witn vaseline.

Cover the lower euriace only with vaseline Cover the upper surface only with vaseline Do not cover any part (control leaf), Cover the cut end of leaf-stalk (petiole. of all leaves with vaseline to prevent anTM evaporation from this end.

Hang all the leaves by means of threads from a sup- port (stick) and leave them aside in the Laboratory for a few days. The following conditions will be noticed:

117

(111,

(iv)

molili neatider Fresh ag thế

Nearly as fresh as hd 1 3hrivelled up Completely dried

day?

rop the arve experiment it can be concluded that me leaves (1) & (ii) whose stomatal openings were oked with vaseline could not transpire and henge he water contents were conserved and the leaves remained fresh In leaves (iii) & (iv) the stomatal >penints were left open and therefore they lost their water contents by transpiring through these spenings and dried up. Therefore transpiration takes place through the stomata,

-Vaseline

Porubberi Tubing

*CONTROL

Vaseline on Upper surve

ONG KO

四期星

牙小學 附各西腺聲。數醒咋

日十二月四年七六九一郿公年六十五國民莘中

世港 加微

比賽筷下中气

分之出

,網名類: 小樂次

一般下樂區學校觀有沉大海

大會堂座無虛設

觀衆報以熱烈掌聲,

倫男。

y.T.Explain how hate of. Transpiration:could be

measuredt

英中時事問答

英華對聖保羅

[POTOMETER EXPERIMENT TO SHOW RATE OF TRANSPIRATION,

used by win

Lo measure

the rate

A Potometer was lof water absopt ion by a plant. Since the rate of

Transpiration is the same as the rate of Absorption the same experiment can be used to illustrate both.

There are many kinds of potometers but the principa under lying their working is the same, Shown LA sketch is one of them used for the above expt. EXPERIMENT: A large glass tube with a side arm bent upwards parallel to it is filled with preboiled cold) water. A leafy shoot is selected and cut away from the mother plant under water. The glass apparatus is completely immersed under water and the leafy shoot fitted into the rubber stopper in the upper end of the 5 de arm. A glass capillary tube is filled with

and fitted into the rubber stopper in the lowT end of the main tube (also under water). The upper end of the main tube is closed with a rubber! stopper. After immer sing the free end of the capil lary the under water in a dish the whole apparatus is removed from under water. All these precautions, are taken to eliminate the risk of allowing any air bubble to remain in any part of the whole apparatus The branch is fixed in the side arm so that in case any air bubbles arise in the water they; would rise, lup into the straight ma in tube!

Wirt

The apparatus is left in a quiet comer of the laby for some time!

Then after colouring the "water"in the dish with some dye the end of the capillary tube is momentarily taken out of the water to enable a little.

to be drawn in to form an air bubble it is immersed back in water the bubble can be observed moving along the capillary tube. Thus, if

air

Then when.

la kept and volume known (by finding diameter capillary tube and adjusting a scale behind it), Wolume of water transpired in a given time coule und. This would be the hate, of Transpiration of

plant.

BRARIES

li

da

Ri

R11 = R2 X

L2.

重複實驗以求R.平均值

3. 解

設AB'

A

两点之

電位差

14

B.VAB

通過R.

Hillili

RR

之電流分別為

R

RA

Ra

Re

B

120x30

12叽:

20130

15:23

R1211=112[773]

R1234-1 15 X 30

== 102 15.+30

RAB = 101+13743=43745]^»

E=6+18 14 M

Y = 0·3x-3)=0.15 ng

{y}= 0.15]+ 4×0.1=10.55]2

(Tamp

RA 14. VABER XI = 13.45.x1=13.45 vr

FRAXI

(b) Is

TRONSP

·Vac = VAB - Is Rs=13.45-3-45

= 10 V.

Riza

15.43

2

13 = 10 = = = = amp:

15

3

VAD = VAC - Is R1 = 10-2 = 8 v.

工

8

= 0.4`amp.. -201

C.電流之热、化學、磁效应填-

題

1. 電流通过導線時,所生之热量与

導線之電阻及經展

之时间成正比,

導線两端之電位差每ī伏特若其 上之電流為1安培時則該導線每 紗可生热量為

2.用110V面功率為60W之灯泡接拎

220V.之電源上,其光亮程度較 君接於80V.之電源上則光亮程度 較

3.電解時所析出物質的量与通過

之電流及時间之乘積成比、

電解時在目極上澱精之物質芒為

Shoot

•Rubber stoppec'

POTOMETER

·Air Bubble Scale

(TO SHOW RATE OF TRANSI?)

Waler

2.1.Give an Experiment to show Anaerobic Respiration.

2.11.Show by Experiment that Heat is given out during

Respiration What is the importance of Respiration.

!兔子重時,則通過之電

4. 電阻為5几之電線,若通入zamp.

之電流則每秒可生热4.8卡,則電阻 8丸之電線,通入305 amp. 電流時 秒可生热

5. 電压為220v.之灯泡一為100w

60w,其電阻各為

續用20小時,用電失 設每度0.28元,須費.

及

若速

即

元

度

6.銀鹽類溶液内通以1安培之電流

积 導線周周一点之磁場强

欲析1克之純銀,則須時

7. 載流長直導線周圍

度与

此係称為

8

成正比,而与

成反比

————定律.

半徑為一類之图形線圈其上浴 通过人安培之電流時則圈中心之 磁場強度為 ·奥斯特 9.用右手握螺線管若以弯曲之四指 表電流之方向則拇指伸直時所指 者即為一柱,此阅係称為定

定思 16. 圈轉式電流計又称電流計

其構造原理係依据線圈在磁場中 所生之轉角与 成正比

xx