百二第四第
日二初月四年午丙曆發
WAH KIU YAT PO
華僑教育
英中會考物理科試題
PHYSICS.
Time allowed - Two hours and thirty minutes
Answer-FIVE questions, choosing at least ONE from each section. Mathematical Tables will he supplieds, Graph Paper will be supplied on request,
SECTION A
2.
(c)
(a) A cargo airesaft is due to leave Airport A at 10.00 hrs and to arrive at Airport B at 11, 00 hrs., Airport B is situated 200 miles from Airport A in the. direction 28 East of North, The wind is blowing at a speed of 50 m. p. b. from the North West.
(1)
(ii)
In what direction must the aircraft fly to reach Airport B. At what average speed must the aircraft travel to arrive at Airport B at the estimated time.
Solve by use of a clearly labelled vector diagram drawn to a scale of 2" 100 m. p. h. and explain your construction.
(b) A car starts from rest and accelerates uniformly at the rate of 6 ft. per sac. per sec. for 10 seconds It then travels at a constant speed for 30 seconds after which the brakes of the car are applied and the car comes to rest decel- erating uniformly in 8 seconds.
Draw a' Velocity-Time Graph and from this determine:-
(i)
the maximum speed reached in m, p. h.
(ii)
(1)
(Li).
the total distance covered, indicating how this is found from the diagram.
Quoto two examples in which friction is helpful in producing motion, A rectangular block of wood on an inclined plane is on the point of aliding down the plane, Draw a clearly labelled diagram showing the forces acting on the block,
.1
(i) If the coefficient of friction is what is the angle of inclination of
the plane to, the horizontal?
{a} A block has a mass of 24 gma, and a volume of 20 c.c.
a liquid the block floats, the volume submerged being.15 c.6.
! Calculate:
the density of the solid.
(ii) the density of the liquid.
When placed in
(iii) the additional force required to svomerge the
block completely
D
(b)
AB and CD are run flat rigid strips of metal of negligible thickness and uniform width AB is wire the length of CD and the two strips are fixed together ar rish, ngtes so that CA = AD.
Calculate
713
the position of the centre of gravity of the flou se formed (diagram above).
(13)
the angle in degrees of AB to ine vertical wher the figure is suspended from the point C.
(1) The handle or screw press in 1 ft. long from end to end and the
erzáw has 12 threade to 1′′ What is the Velocity Ratio of the press 7.
Screw Press
-Handle 1
Screw
ION
(ii) Each plate of the press has a diameter of 1 ft. and the fores
applied to each end of the handle is 20 lb, wt.
Assuming an efficiency of 40 per cent, what will be the pressure exerted by the plates in ib, wt. faq. inch ?
(a) Draw a labelled diagram or a hydraulic (Bramah) press showing how an
such as a bale of cotton, can be compressed.·
object, such as the
(b) The larger cylindrical piston fram) of a hydraulic press has a diameter of 1 ft, and the smaller piston (plunger) a diameter of 2 in
Calculate:
(1)
the upward thrust of the tum when a force of
100 lb. wt. is applied to the plunger.
(i) the distance moved by the ram when the plunger
"movea' 2 ft.
(c). The apparatus shown can be used, when sssembled, to perform an axperiment to show the variation of pressure with depth in a fiquid,
Draw a diagram to show how you would assemble the apparatus and describe fully how you would use af to perform such an experiment.
clamp
Spring Balance
Rad
Beakez
Uniform Glass Tube 3cm;
ext. diameter, One and of nibe tại ben ground flat.
Rigid Brass..
Disc 3.2eme diameter with
loop at centre of ons face,
(a) Exolaio the differences between evaporation and boiling.
(1) Give two definitions of Relative Humidity.. (11) What do you understand by the Dew Point 7
(c) Draw a labelled diagram of the apparatus you would require to determine
the Relative Humidity of a room and describe how you would make the necessary measurements.
(d)
Temp (*G#
11
12
13
WP (mm.) 9.8 10 5
14 LIS 16 17 já
11.212.9 12.8 13.6 14,5 15.5 16,5
19
20
11,5
The table given above is an extract from a table showing the approximate Vapour Pressure of Water over a range of temperatures the temperature of a roogi le 18 °C and the Dew Point is 14°C, what is the Relative Humidity of the atmosphere of the room?
(e) Water is introduced, drop by drop. Into the space above the mercury in a mercury barometer tube until a thin film of liquid is formed and remains on. the surface of the mercury Explain clearly what banne durise this procedure.
What will happens the barometer tube is heated in a steam jacket if sufficient water remains in the barometer übe to maintain throughout a film of liquid on the surface of the mercury even at 100°C 7.
SECTION C
6.
(a) When the stem of a vibrating tuning fork is pressed against a table,' the sound can be heard very clearly. The length of time during which the sound can be heard would be longer if the vibrating fork were not pressed-against -the table. Explain these facts,
(b) What is the relationship between the frequency of vibration of a stretched wire and:
(1)
the length of the wire.
(ii) the tension in the wire;
(c) Describe fully an experiment you would perform to show the relationship referred to in buli)
(d) A and B are two observers one kilometre apart. There is a steady winė blowing. When a gun is fired by A, the time interval between the flash and the report observed by Bis:3.04 sec. When a gun is fired by B. the interval between the flash and the report observed by A is 2.96 sec Calculate the velocity of sound in air and the velocity component of the wind in the direction BA
(3) A thin convex lens of focal length 17,5 mm, and fitted with a stop (diaphragm) which reduces its aperture to 12 mm. is placed with its principal axis horizontal. A point source delight P is placed 5 mm. above the principal axis and 10 mm. from the Central plane of the lens)
my means of a ray diagramp (örawn to a scale of 1 in. * 1 cra¿] find;"
(1)
the position of the image of P.
the height of the patch of light which is formed on a vertical screen placed 20 mm, from the mens and on the side opposite to Pa
Give the lens equation and state what each letter represents. State clearly what sign convention you would use an
me to the lens equation, check your answer to (ef(1),
(c) Draw an experiments arrangement assigned to produce, on a woréen, • pure spectrum from a narrow sitt source of white light.
Explain why this spectrum is composed of a series of images of the source in different colours.
A ray of Laonochromatic light is incident on one face of a parallel sided: glass black at an angle of incidence of 45. The refrasive index of the glass 11.5, Find the angle of refraction by means of a graphical construction without reference to patheroatical tables.
(b) A rectangular block of transparans plastic, whose refractive index is less than that of glass, is now placed con Act wis the glass block as shown in the figure. Copy the figure; skotch the subsequent track, the rugh both blocks, of the incident ray (angle of incidence 45 ) No graphical construction is Toquired. The angle of emergenc from the plastic block is one of the following: (i) greater than, (ii) equal to, (ii) lesa than, the angle of incide on the glass block State which of these is true in your diagrama:
Incident Ray
Cans BlockY
Transparent Plastic Block
(c) Draw a labelled diagram to show the optical working of a simple form of projection lantern;"
Indicate in your diagram and explain the function of the condenser fona (or lenses).
(d) The image of a slide 33" is projected by a lantern on to a séresn 10 ft. x 10 st. placed at a distance of 30 ft. from the lantern. What is the focal length of the front tens of the lantern if the image just fills the screen ?.
SECTION D
教育之不易爲 關係、挨家逐戸派章程 使人深感私營 張貼街招、刊登廣告、與小學校長拉
辦學原非易,今年倍覺難!
學校增加社會復不景 私校招生須費大氣力
FEARE 祝成立十年 10
COBR
山 生學校中,大布居私, ,已紛紛作招生滋聲,招生簡章,以凌招徠的招生名額,全部馬學年烯,大發來說,在致蒞班主共兩類, ,對介紹學生。此械九學年斷方面,均由教會主辦的學校,各院校同學及各界人 日舉行慶祝成立十週
(牾院)目前踞然身解數,除了張貼輯時,就在钳淼的爻: 私立學校方面, 距離暑假,尙有一段 知及在薇野上登出互,記者患然沒有地從年籣限併,大發無甚大學新亞書院公段調 紅的赫對,但起碼索過問題。
NRG 174 R5
有時,有空軍部八百人,雖然該校 至於幼雅區的7年念,壽險伯良
日一廿月五年六六九一腿公年五十五國戾叢中
生源社象上每班。部牟因招立生現
派發報名那一天,
月,由於學校日多,而此是其門如市。本港
熱灣廣控
生貼告、
2 BASKIKKE
,即使相
被收容入學。 大學。(琳) 這两類區锬,有多 蔫十餘日,亦不取錄。
K
·際分二元,四元晚
【 瑪利諾神父會
劉登報招生,而易於幼稚育不多,該係 。阻些學校的中一年。一些私立幼稚園, 班學位,Ü年都是不亦開始招生。本非由
觀利
阿娟 觀塘設工業校
學雜
新區家長甚歡迎
公缐分
樂藝撒
日,张,乃不能不出晝校,幼稚園部份招生以來, KURT GENZEVUSH CRTRAIT CERTA 【國際肚) 與子弟不少,會一
人大名瑗語包慶開
英中會考經濟及公共事務科答案(繽
SECTION B
Economic and Public Affairs.}
Answer Question 5. 6 and 7 in essay form.
5. (a) What are the main functions of money?
in the complex Industrial order it is impossible to carry on trade by means of bater system. It has therefore been found convenient to accept one thing as the standerd medium for all exchange transactions. That which is used for this purpose is called money. The universal use of money in commerce aids immensely the processes of exchange. Our manufacturer of cotton yarns, who wants rice, motor cars and pleasure trips, would find it awkward to trade. his yarns for those articles, but when he sells his yarns. for money, and with the money purchases the things he wants the transaction is easy enough. It is a function of money then, to act as a medium of exchange.
In the process of exchange it is necessary to nave some means of comparing values of the goods to be exchanged, Otherwise one would not know how many eggs to exchange for a bag of rice, or how many pairs of shoes for a suit of clothes. When a standard medium of exchange has been adopted by law or general consent, it is possible to express the value of every good in term of it. There then exists a common measure of values by which one good can - instantly be compared for purposes of exchange with any other good. When the value of good is thus expressed in terms of money it is called a price. In Hong Kong we have dollar as our monetary unit. Thus we know that if the price of a suit of clothes is fifty dollars and the price, of a pair of shoes is ten dollars, the value of the sult is five times that of the shoës; and it will take five pairs of shoes to exchange for one suit of clothes. It is a second function of money, then, to serve as a standard of values
If you owes someone debt, you can pay that debt by offering money. Then money can be used as a standard for deferred payment...
Finally when money becomes generally acceptable those who want to provide for their future needs begins to store. up money because they can exchange for the thing they might need. (b) What benifits does a country gain from taking part in
international trade?
It is sometimes thought that in an exchange transaction between two countries, one of them must be the gainer and the other a loser. Such is not the case. In a fair exchange" both parties are benefited.
Men live together in cities and towns to earn their living at all kinds of work whilst other men do other kinds we are ally more and more dependent on the work of others to give us all we need. To-day raw materials used in factory may come from different parts of the world. The producers have to collect, prepare and pack into bags which are sent to the manufactureer by importers and exporters. Men have had to be paid for producing the goods, for collecting and delivering their and for getting their ready to the factories. The men who transport the raw materials from the producers to the factories by, land rail and road are to be paid.
The raw materials are now ready to make into finished goode. This work has required wages for workers, money to pay for the machines, and for their repair, for electricity, lightning and many other things that make a factory work. When the finished goods have made by the manfacturers, tha wholesalers, the transactions are usually passed through the hands of an importer and an exporter.
All these consumer's goods, raw materials for
flourishing the development of industries, and all forms) of transoort that serve us are the products of international trade.
Commerce is the moving of goods from the man who, wants to sell to the man who is willing to buy, the passage of goods from produce through. the manufacturers to the consumer may be a long and complicated one. It the function of the international trade to provide complex machinery needed for all this.
Retort Stand
SECTION B
Length of -Strong
Thrand,
Pisase turn over."
(a) State clearly what you understand by "the casfficient of apparent expansion of a liquid"
(b) Describe fully an experiment to determine the coefficient of expansion of a non-volatile liquid.
-srawin labelled diagram of the apparatus you would employ
apparent
Using symbols insteăn oi auzumi Vammen, give the readings which "must be taken and show,how the result can be deduced from these readings,
IC) Express matramatically Doyle's Law and Charles' Law, writing a daparate equation for exch indicate the meaning of the symbols usad. "State the conditions under which each law holde
Show how the fuil gae equation deduced from these wo lawa
PV.
1
» K.. for a fixed mass of gas, can be
Fig (1)
Fig (ii)
Fig (1)
Fig (lv)
2020
ta) ABCD's a coil of wize which lies so that it can be rotated on axia XT between the North and South poles of a strong magnet....
Draw figures (1) to (iv) and on each indicate with arrows the direction of the current flowing through the coil when the coil is moving through the positions shown in those figürsse
(b) With the aid of a labelled diagram, describe the working of a simple form of direct current motor
(a) Would the motor which you describe act as a generator if the supply of electric current to it were stopped and the armature of the motor were turned mechanically... Give reasons for your answer,
(4) Copy out and complete the following sentence, "In the nickel-iron (Edison) Accumulator Call. the charged positive plate contains
and the negative plate contains ‚.......... you and the electrolyte 18
...(0]
State one purpose for which nickel-iron accumulators are particolarly suited and give two reasons for your-answIX,
(a) Describes with the aid of a series of simple diagrams, how you would charge a gold leaf electroscope by induction, using a charged ebonite rod, Show on your diagrams the nature of the charge on the rod and the cap and leat of the electroacope...
(b) An electric kettle is made of copper and weighs 800 gms. It contains, 1-25 litres of water at 16*C, When current is switched on, the kettie will boll in Pminutes Neglecting heat losses find the electric power required. (Specific Hear of Copper-0-10. Mechanical Equivalent of Heat 412joules/cal)
(c) Explain, with the aid of a labelled diagram, how a moving coll loudspeaker works.
(d) if you were provided with a milliantmeter of resistance 5 ohms and futt scate defieeston 10 milliamperes, how would you modify this so that you could use it to moast; a potensial difference of 20 volts 7.....
(Give in full any necessary calculations)
No comments yet.
Private notes are available after approval.