一圆筒形容器内装有水 圆筒内横截面积为厘米（A cylindrical container is equipped with a water cylinder with a cross-sectional area ofcm）

1、一圆筒形容器内装有水 圆筒内横截面积为100厘米（A cylindrical container is equipped with a water cylinder with a cross-sectional area of 100 cm）Own collectionThink it's usefulSo upload it to BaiduShare it with you!Zhejiang third junior high school natural science competition test questionsFirst, the choice (30 itemsEv

2、ery day 2A total of 60 points1. The electric fan hanging on the ceiling of the roomThe tensile force of the hanger to the ceiling is F1The electric fan rotates horizontally and uniformlyThe pulling force of the boom to the ceiling is F2Then ()A, F1 = F2 B, F1 > F2 C, F1 < F2 D, lack of conditi

3、onUnable to compare2. When an ordinary household incandescent lamp is in normal lightThe current intensity through it is about ()A, 2 x 102, B, 2 x 10, C, 2 x 10-1, D, 2 x 10-23 and 1999 will return to the motherland of MacaoThe temperature zone and the dry wet zone are respectively ()A, subtropical

4、 zone, humid zone, B, tropical and humid areaC, subtropical, semi humid area D, tropical and semi humid area4. The following animalsIn his lifeThe use of three organs as a respiratory organ (the exchange of blood with the outside air) is ()A, mammalian B, fish C, amphibian D, birds5, the following:

5、(1) coal combustion; industrial emissions arbitrary emissions; set off firecrackers; aircraft, automobile exhaust emissionsWhat may cause air pollution is ()A, only one, B, only C, only one, two, three, D, one, two, four6, refrigerator refrigerants, methyl chloride in the high altitude by ultraviole

6、t radiation to produce Cl atomsAnd the following reactions: Cl+O3 to ClO+O2ClO+O to Cl+O2The following statement is incorrectA and B are the catalysts for the total reaction, and O3 is converted into O2 after the reactionC and Cl atoms are the catalysts for the total reaction, and D and Cl atoms dec

7、ompose O3 repeatedly7. On a flat highway, the speed of a bicycle running at a constant speed is about 0.02 times the total weight of the carThe rider's power is closest to that of the cyclistA, 5 watts B, 50 watts C, 500 watts D, 1 kW8, summerThe highest temperature in our province is not at 12:

8、00 noon, the strongest solar radiationIt's 13:00-14:00 in the afternoonThis is mainly because ()A, urban street shade B, urban stroke fasterC, a large population in the city, D, urban building materials have larger specific heat9. As shown in figure C, the elbow is filled with waterClose both a

9、and B valvesVertical placementIf you open the valve B first, then open the AWater will ()Outflow at A and BA does not flow outB and B do not flow outOutflow at aC, two out of placeD, two do not flow out10, people sitting in a dark tinted glass car can see people outside the carAnd people outside the

10、 car are not easy to see people in the carThe explanation for this phenomenon is correct(1) the light that goes out of the car is absorbed into the part of the tinted glassThe people in the car were exposed to weaker light; (2) the light reflected from the stranger to the dark glass was stronger tha

11、n the light reflected on the tinted glass; (3) the inside of the car was darker than the car outsideMy wife's pupil is bigger than the outsideA, only (1) (2) B, and only (1) (3)C, only (2) (3) D, (1) (2) (3)Rated voltage 11, an amplifier is 110 VoltsThe rated power is 100 wattsThe current supply

12、 voltage is 220 voltsIf you use a bulb to reduce blood pressureWhich of the following application of series bulb and the most suitable amplifiers ()A, 110 volts, 200 watts, B, 220 volts, 100 wattsC, 220 volts, 400 watts, D, 220 volts, 200 WATTS12. The following statement is correctA, the reaction be

13、tween the formation of salt and water is called neutralizationThe reactions of B and all salts are complex decomposition reactionsThe reactions of C and any single element are replacement reactionsD, where all the oxygen is involved, is an oxidation reaction13. The composition of a compound (some ac

14、id refers to solute)It must contain hydrogenDo not always contain oxygen is the alkali acid the acid oxide and salt in the salt and ammonium salt, hydrate (crystallization)A, the only B, only the second.C, the D, the only the only one14. A and B are two piers on a straight riverA in the upper reache

15、sB in the lower reachesThere is a ship sailing at a speed of V in the still water, from pier one to pier B.After arriving at pier BReturn to pier one immediatelyA trip back and forth time is tIf the distance between a and B is SThere are ()A, t > 2S/V B, t = 2S/VC, T < 2S/V D, above three kind

16、s are possible15. Use a DC motor to lift the weight of 200 kgRead parallel to both ends of the motor, voltmeter reading is 220 voltsThe ammeter reading in series in the motor circuit is 5 ampereIf the motor within 8 seconds will lift 4 metersThe resistance and efficiency of the motor are (excluding

17、the energy of frictional losses)A, 48.4 euro 89% B, 4.84 euro 89%C, 1.2 euro 72.7% D, 12 euro 72.7%16. The chemical formula of a salt is MaNbThe ionization equation is correctA, MaNb=aMa+bNb- B, MaNb=bMa-+aNb-C, MaNb=aMb+bNa- D, MaNb=Mb+Na-17, according to the relative molecular mass and elemental v

18、alence has a group of chemical type regular arrangement: CH4, X, H2O, HFAmong them, X should select ()A, HCl B, H2S C, PH3 D, NH3,18, as shown in Fig.The body is pulled by a fixed pulley to weigh 98 cattleWhen the person pulls the rope from A to BThe work done by man on the pull and pull of a rope i

19、s ()A and tensile strength increased graduallyThe work done by pulling force is 98 coke;B, the size of the tension unchangedThe work done by pulling force is 98 coke;C, the size of the tension unchangedThe work done by pulling force is 294 coke;D, the size of the tension unchangedThe work done by pu

20、lling force is 392 cokeSaturated lime water clarified at 19 and 20 degrees CThe following changes took placeThe white turbidity will not appearA, reduce temperature B, raise temperature C, temperature unchangedEvaporation solvent D and pass through CO220, in order to remove the salt in the Ca2+, Mg2

21、+, SO42- and sandSalt can be dissolved in waterThen, the following five operations were performed: 1. Filtration; (2) excessive NaOH solution; (3) adding proper amount of hydrochloric acid; (4) adding excessive Na2CO3 solution; adding too much BaCl2 solutionThe most suitable of the following order o

22、f operations is ()A, D. B. C21, in the early winter seasonFrigid mammalsWill put on a heavy winter clothesTo withstand the cold in winterThe reason why the heavy body hair of animals can defend against cold is ()A can prevent heat conduction and radiation B, and prevent the loss of moisture in the b

23、odyC can prevent heat convection and radiation D, and prevent convection and conduction of heat22, as shown in the circuitConstant supply voltageWhen the slider moves left (P)The number of A and two increaseThe number of B and two is reducedC and current expression increaseDecreasing the number of v

24、oltage representationsD and decrease of current expression numberIncreasing the number of voltage representations23, experts predictThe next few years in ChinaThe number of people with AIDS is likely to increase substantiallyJudging from the situation in our countryThe main reason for this result is

25、 ()(1) injecting drugs into syringes; (2) failing to comply with sexual morality; (3) using blood with AIDS virus; (4) not treating AIDS patients in time; and not restricting the entry of foreigners into the countryA, B, C, D24. The charge number of element X is aIts cation Xm+ is the same as that o

26、f the anion Yn- of the element YThe charge number of the element Y is ()A, a-m-n B, a+m+n C, a+m-n D, a-m+n25, A, B two lights and rheostat as shown in the connectionThe supply voltage remains constantWhen the slide P of the sliding rheostat slides to the rightThe brightness of A and B two lamps wil

27、l be ()The A and A lights dimmedB lights turn onB and A lights turn onB lights dimC, A, B two lights are all brightD, A, B two lights are dimming26. A double layer metal vessel in an adiabatic device as shown in Fig.Pour water into the inner container at a temperature of 20 degrees centigradeThe tem

28、perature is measured by thermometer I, and the water of the same quality is poured into the outer container at a temperature of 80 degrees centigradeMeasurement of temperature by thermometer IIHeat transfer is considered only in the double deck containerThe number of two thermometers recorded at equ

29、al intervalsDraw the hot water cooling curve (expressed in dashed line) and cold water heating curve (expressed in solid line)The image of water temperature in the above four containers, which can best reflect the changes of water temperature in the two containers mentioned above, is the graph27, mi

30、dsummer seasonUnder the scorching sunPeople are swelteringIf we come to Japan under the tree shadeIt will feel coolIn the following factsIt can be used to explain cool sensationsThe light travels in straight lines; the plants can absorb solar energy and transpiration; photosynthesis; the water absor

31、ption of heat in the vaporization; the people rely on sweating to regulate body temperature; the objects in direct sunlight whenMore heat absorbedA, 1 3 4 6 B, the 5 C, the 4 6 D, 3 4 5 6.28, in the food chain of an ecosystemSuch as green plants, mice, snakes, eaglesPhotosynthesis of green plantsCon

32、verting solar energy into chemical energyAnd pass along the food chain step by stepHowever, each class of organisms breathe through itIt's all about energy releasethereforeEnergy decreases gradually in the course of transmissionThisThe following statement is correct ()A, the process of transferr

33、ing energy along the food chainEnergy conservation;B, the process of transferring energy along the food chainEnergy is still conserved;C, the process of transferring energy along the food chainSometimes the conservation of energySometimes it's not conservative;D, the process of transferring ener

34、gy along the food chainThe total energy did not decreaseOn the contrary, it has increased29. Equal volume mixing of two sulfuric acid solutions with mass fractions of 3a% and a%Mass fraction of solute in mixed solution ()A, greater than 2a% B, equal to 2a% C, less than 2a% D, can not be determined30

35、, equal mass of sodium, iron, aluminum, respectively, with a certain amount of equal volume, the concentration of hydrochloric acid reactionThe volume of gas released is unlikely to be ()A, sodium, B, iron, C, aluminum, iron, as much as DTwo, fill in the blanks, short answer questions (the 16 items2

36、 cents per hourA total of 46 points31. The known surface area of the earth is about 5 x 1014 M 2It can be estimated that the total gravity of the atmosphere air is about cattle32, summerIn a sealed, insulated roomKeep the refrigerator door open and run the refrigeratorThe temperature in the room wil

37、l be "elevated" or "reduced" or "unchanged"33. The candle flame is about 30 centimeters away from the convex lens on the spindleGet an inverted image magnificationIt is known that the focal length of the convex lens is within the range of F34, please draw through the op

38、tical path of the lens of the eye35. Express with chemical equation:(1) natural water has a certain self purification capacityInorganic suspended solids such as CaCO3 can react with hydrochloric acid in wastewater:;(2) there are only two elements in three substances known as a, B and CA commonly use

39、d reductant in metallurgical industryPropylene is one of the products of combustion in the airBut not anhydrideB and C will also react under certain conditionsThe chemical equation of the reaction:36, a closed containerSealed with a certain amount of airThere is a bee flying in the container (relati

40、ve to the container)The container is placed on the left side of a precision balance plateBalance after balanceThe bees fell to the bottom of the containerThe balance will be "unbalanced" or "still balanced"37, as shown in the circuitThree meters, R, S, T connection errorTwo lamps

41、 M and N are normally luminousThe readings of R, S and T are 1.5, 1.2 and 2.5, respectivelyThe voltage at both ends of the lamp M is VoltsThe current through the lamp M is safe38. The neutral point of a homogeneous plate with a length of 2 meters is placed on a low fulcrum on the horizontal planeThe

42、re are two children on the flat (pictured)A =30 kg of M is knownThe midpoint of the plateM B =20 kgOn the left of the boardNow two children move slowly to the right at the speed of 0.1 meters per second along the boardThe second plane begins to rotate39. Take the petals of four plantsWere placed in

43、a mortar.Adding alcohol to grindTake a little eachTest with dilute alkali or dilute acidgive the result as followsQuestion: (1) the flower juice that can be used as acid-base indicator; (2) the color of rose juice added with sodium bicarbonate isTypes of flowersFlower juice in alcoholColor inFlower

44、juice in acidColor inFlowers juice in alkaliColor inBig red flowerPinkOrangeGreenRosePinkPinkGreenMarigoldYellowYellowYellowDaisyColorlessColorlessYellow40, a small light bulb marked with "4V 2W" is connected to L as shown in the circuitWhen both S1 and S2 are closedThe ratio of electric p

45、ower consumed by R1 and R2 is 2:1; when both S1 and S2 are switched offThe ratio of electric power consumed by R1 and L is 5:1And small bulbs emit light normallyThe resistance value of the resistance R2 is Ohm41, a mixed gasIt may contain one or more of H2, N2, CO, CO2 and HCl gasesThe gas is tested

46、 by the following deviceThe experimental phenomena are as follows: no precipitation at A; white precipitate at B; red black at D; blue at E; white precipitate at FThen:(1) there must be a mixture of gasesMust not exist;(2) write out the chemical equation of the reaction at D42, as shown in Fig.Known

47、 R1=2 ouR3=7 ouThe voltmeter V1 shows a value of 4 VoltsThe number of V2 is 8 VoltsThe resistance value of the resistance R2 is Ohm43, a student at room temperature with the following experiments to prove that microorganisms in the soilQ: (1) when the experiment startedThe only difference between th

48、e test tube and the test tube is; (2) 48 hours laterIt is expected that the observed results are; (3) the experiment can prove that the reason for microorganisms in the soil is44. The experimental device on the right shows good air tightnessThe experimental drugs and dosage are shown in FigureWhen t

49、he piston of the Kai Pu generator is openedThe clarified lime water in the reagent bottle has not been turbidWhy is that?45, a cylindrical container containing waterThe cross sectional area of the cylinder is 100 cm 2Ice mixed with stone is put into the water in the barrelJust suspended in waterIt w

50、as found that the water in the barrel rose 6 centimeters; when the ice melted completelyThe water surface fell 0.56 centimetersThe density of ice is 0.9 * 103 kg / M 3The density of the stone is46, there are two soluble compounds A and BThey have a series of transformation relationshipsInfer the che

51、mical formula of A and BThree, analysis and calculation (the 7 itemsThe 47-50 of the 6 a.The fifty-first, fifty-second day of the 7Fifty-third questions 6A total of 44 points47. A flat mirror AB with a length of 5 cm is placed on a horizontal groundA long slender rod A is erected at the E point 10 c

52、m away from the EFA line light source parallel to the AB mirror is placed at a distance of 5 cm away from the B CDCD=5 cmThe distance from the horizontal ground is 18 cmFigureThe line light source, the mirror and the thin rod are all on the same planeHow long is the length of a slender rod illuminat

53、ed by reflected light? And make the light path on the map48. Hydrogen is a clean energy sourceThe combustion value is 1.43 x 108 kJ / kgMost of the hydrogen on the earth exists in the form of a combined state (mainly water)In the development of hydrogen energyHydrogen is obtained by electrolysis of

54、water (at 20 thousand volts)500 ah9 tons of electrolytic water in 24 hoursIs this method valuable?49, (1) the sample decomposition of pure calcium for a period of time at high temperatureCool and weigh the remaining solidsThe quality is half of the original samplePlease analyze the composition of the solid (write chemical formula); (2) T C to a copper sulfate unsaturated solut