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The mid-term character of junior high school in Lung-chuan measures to review in the spring of 2005
The grade eight physics tries
(The time limit 60 minutes full marks 100 cent)2005-4-19

The class score of the name registration number
A, fill blank
1, install to illuminate the electric wire that the electric circuit use, the its Xin line does with the metals, Xin line outside what to wrap be the 1 F rubber or plastics, this is because metals BE______body, rubber or plastics BE______body.
2, please enumerate at least two household-use heaters which contribute efforts to us:__________, ________;The television will have fever when the television switch on electricity, but we don't hope it of the temperature lead Gao, so at it of outer shell up have_____________, in addition, whether you adopts other ways to reduce the heat or not, write a kind of way of doing:___________________.
3, the some conductor connects on the electric circuit China Times with 20 Vs, electric current strength is 2 As;If want to make the electric current strength of pass that conductor change into a 0.5 As, then the electric voltage that conductor both ends add should be_______V;If the electric voltage that the conductor's both ends add for 0, then its resistivity is_______Ω .
4, occurrence in the family electric circuit______(fill "short circuit" or"break road")BE an electric current in the electric circuit lead big of a reason, another reason uses an electric appliances_______lead greatly.
5, the electric voltage of one section dry battery BE_____Fu, only have to be no higher than______the electric voltage of Fu is safe to the human body.
6, a classmate home, copy form at the end of last month, electricity degree show of form number BE(the double is inside frame
Show the number is a fraction).When the end of this month copied form, electricity degree show of form number BE.That family uses an electricity in this month_____degree.
7, you must once observe the power supply circuit of your home.The insurance device of your house BE______, be electric circuit in_______, it will cut off electric circuit.
Two, single-item choice
8, concerning the magnetic field, following parlance inaccuracy BE()
A, the Ci body around exists magnetic field B, the surroundings of electric current has no magnetic field
C, Ci body the interaction of passes magnetic field occurrence
D, terrestrial magnetism field with switch on electricity the magnetic fields of spiral line tube all the magnetic field of the form magnetic iron alike with
9, concerning the Ci line, following parlance inaccuracy BE()
A, use the Ci line can show the direction of magnetic field by image earth's surface with it of distribute a circumstance
B, the Ci line is the reality existent line in the magnetic field
C, the Ci line out of the Ci body always sets out to return to a S pole very much from the N
D, the Ci line direction of terrestrial magnetism field from geography the South pole neighborhood of a certain set out to return to geography neighborhood in North Pole a certain of
10, use following which device can directly recognize a front line with zero lines()
A, electric current form B, electric voltage form C, electric power form D, try an electricity pen
11, every year of our country battery consume the quantity reach to 14,000,000,000, some cities have already established to discard battery to procure a station, it main purpose BE()
A, re- process new battery B with the economy cost, prevent°from battery in of some materials result in pollution of the environment
C, refine an useful material D, carry on battery function to investigate to improve a new product
12, relevant semi-conductor, the following parlance is false BE()
A, the semi-conductor conducts electricity function to be subjected to temperature, only shine on influence of wait the outside factor to far compare conductor, the insulator greatly has to be many
B, the CDS in the building way auto switch is a semi-conductor
C, the integrated circuit is the D which does with the semi-conductor material, the semi-conductor is smaller than the electric resistance of superconductive material
Three, Jian3 Da Ti2(contain an on-line to make a diagram, total 18 cents)
13, chase the following the object electric current concerning object, electric resistance, give or get an electric shock the value with the the most close power to connect with the line.(6 cents)
14, have a just the electric stove in work.(4 cents)
(1)If carelessly touch the both ends of electric stove silk together, will take place what phenomenon do to have so what result
(2)The material which creates electric stove silk should have which characteristicses
15, mark clearly magnetic pole in the A diagram, mark clearly the N of small magnetic needle in the B diagram, S pole.(4 cents)
16, the underneath is the electricity charges voucher in some classmate April, on these grounds voucher, you can get which useful informations.(write 2:00)(4 cents)
Province power company electricity charges invoice in the Hubei
Door number:5600001001004, accept a payment for day:the 2004-04-10 NO.s be 1000031434< BRs>
Unit price
Amount of money
Code
466
Feng segment
8
0.8911
7.13
At least
426
Valley segment
32
0.4691
15.01
Magnification
1
Have no achievement
0
The electricity measure
40
Add up amount of money: 22 dollars one Cape four cents
(1)____________________________________________________
(2)____________________________________________________
Four, process and investigation(total 14 cent)
17, please create a mariner's compass with the familiar device in the life, request to speak a device, main step, draw a sketch plan.(4 cents)
18, the small noon classmate wants to use an experiment to investigate iron heart of thick thin please design for him to the influence of the electromagnets magnetism strong or weaks, write an investigation process.(6 cents)
(1)The device that the experiment need:
(2)Investigate the electric circuit diagram of design:
(3)Main operation step:
19, the some material graduate school did to as follows test for the sake of the research light silk influence of the temperature upon the incandescent lamp average service life: keep press of sloth air inside the lamp bulb strong to press for 0.1 atmospheres, the Wu silk is thick thin pass change the size of electric current in the Wu silk to change the temperature of light silk for 250 μ ms, measure average service life and light silk temperature of lamp bulb and electric current of the relation is shown as watch below:(4 cent)
Light silk temperature(℃)
Electric current(A)
Average service life(h)
2200
6.05
8000
2400
6.61
380
2600
7.48
30
2800
8.34
3.5
(1)Analyzing experiment income a data can predict: at with above-mentioned test under the same condition, Wu silk temperature at 2000 ℃ , it average service life in response to the most close in()
A,50h B,500h C,8000h D,16000h
(2)Jian3 Shu4 does a reason of above-mentioned estimate.
Five, reading analysis(total 6 cent)
Electrolysis Lian aluminum
Our home articles is a lot of to all make in to°from the metals aluminum, along with life level of exaltation, various aluminum and product more and more, such as aluminum metal alloy window.So metals aluminum how the production come out of
The originally industrial Lian aluminum is mainly the chemistry effect which makes use of electric current.The raw material that it use oxidizes aluminum(Al2 O3), oxidize the aluminum(Al2 O3) is an aluminum soil the mineral pass "dissolve" to wait a kind of white powder that various craft processings get with"bake to burn" and oxidize an aluminum melting point very high, reach to 2050 ℃ , don't dissolve after water, but oxidizing aluminum powder canning be fuse with partly in the melting point lowerly the ice the crystal stone meltdown the liquid, becoming an even Rong body, being a Rong body to open into direct current at two very up occurrence electricity chemical reaction.Get metals aluminum, the anode output oxygen and anode piece in the cathode-carbon piece occurrence respond, born carbon monoxide and carbon dioxide exhaust atmosphere.
The main equipments of industrial Lian aluminum is an electrolysis slot, treat electrolysis slot as to use an electric appliances and the of electrolysis slot and electrolysis slot establish.For the sake of exaltation unit time original aluminum yield, exaltation energy make use of, as far as possible reduce pollution of the environment, the series electrolysis slot pass of electric current very big, the modern electrolysis aluminum produces electric current that win electrolysis slot's pass some already 160 KAs above, but each the set electrolysis slot electric voltage only the 4 Vs be or so.The aluminum electrolysis stone is a hing energy-consuming business enterprise, the aluminum electrolysis produce medium the electricity charges take up 40% of the cost and the economy energy declines to consume the topic that is an each electrolysis aluminum factory the abyss of time.If make the electrolysis slot average electric resistance lower 10-6 Ωs because of the technique improvement, suppose aluminum electrolysis the factory contain 100 electrolysis slots like this, so that factory a day 24 hour can the stanza electricity △ Q=100 · Rs with 2 · Is ·t=100(160000 As)2< BRs>
·10-6 Ωs ·the 24 h ÷ 1000=60000 kWhs, if give or get an electric shock 0.2 dollars to account by each one can save an electricity to waste to use to be close to 12,000 dollars for a day, the effect is very considerable.
For letting up electric power is lead on-line loss, from commutate a car arrive electrolysis slot of lead line, and the lead of line of electrolysis slot and electrolysis slot make out very thick, it the horizontal piece noodles can reach to a 0.485 ms 2, so thickly led line to outrun us the concept of "lead line" build up usually, but become a sign in fact of"conductor", if you walk into an electrolysis car it is thus clear that arrive these is make into by the metals aluminum material of long pillar body, the workers call it is the electrolysis female line.
(1)Article's speaking of industrial Lian aluminum is the chemistry effect which makes use of electric current, do you still know other effects of electric current each raise 1, and explain that they are electric currents of what effect
(2)Say in the material, for the sake of the decrease loss, the workers make"lead line" into "conductor", this is why
Six, application and practice(total 12 cent)
21, the small Hua brought from the home 2 can not tell from the shape what differentiation of the domestic expenses illuminate an incandescent lamp bubble, and have already seen not pure ir Mingses a card.How judge which lamp bulb of electric resistance greatly please write you of judgment method and basis.(4 cents)
22, small quick practice outside a lesson in want to estimate to measure the electricity power of the refrigerator of his home.Through prognosticate, the compressor works for 5 minutes in a row, the aluminum dish of electric power form turned 60 turn, mark "3600 Rs/KW · h" on the electric power form.(8 cents)
(1)The power of the refrigerator of his house is much big
(2)Small quick is an observant and conscientious person, he conveniently checked to seek once the usage manual of the refrigerator, up mark the sum of refrigerator to make to order the cold power as 210 Ws, contrasted to just compute of the power value of refrigerator, invite you analytical appear this error margin all of a sudden of the reason may have which
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