Xuzhou 20 10 junior high school graduation entrance examination
Physics examination questions
First, multiple-choice questions (only one option in each small question meets the meaning of the question; 2 points for each small question, ***40 points)
1. Soap film can be used to simulate the eardrum of human ears when exploring how human ears hear sound. As shown in the figure, when the speaker sounds, the soap film will
A. vibration
B. Continue to move to the left
C. Continue to move to the right
D. stand still
2. Drop some alcohol into the plastic bag, flatten the bag, tighten the mouth of the bag, and then put it in hot water. After a while, the plastic bags bulged, mainly because of alcohol.
A. melting B. solidification C. vaporization D. liquefaction
3. The following phenomena can't explain the random motion of molecules.
A. red ink is dispersed in water. B. The delicious food smells good.
C. vinegar and soy sauce can be distinguished by smell. D. dust flies when the wind blows.
4. As shown in the figure, tie one end of a plastic rope, tear it into many filaments from the other end, and touch it from top to bottom with dry hands several times, and find that the filaments are open. The reason why the filaments are open is that
A. Heterogeneous charges attract each other
B. Like charges repel each other
C. intermolecular repulsion
D. atmospheric pressure effect
5. During the movement of the following objects, the movement state will not change.
A. the basketball fell from the basket. The rocket was launched.
C. The moon goes around the earth. D. The train runs at a constant speed on the straight track.
6. Some buses are equipped with escape hammers. In case of emergency, passengers can break the window glass with an escape hammer to escape. In order to break the glass more easily, the shape of the escape hammer should be selected as shown in the figure.
7. There are many similarities between the track and the waterway. The valve in the loop is similar to the valve in the waterway, as shown in the figure.
A. Power supply B. Electrical appliances
C. Switch D. Conductor
8. As shown in the figure, the voltage of the power supply is constant. After the switch is closed, the reading of the voltmeter is in the process of sliding the slider P of the sliding rheostat to the right.
A. get smaller. Become bigger
C. First get smaller, then get bigger D. First get bigger, then get smaller.
9. When installing the DC motor model, which of the following factors will change the rotation direction of the DC motor?
A. the magnitude and direction of current
C. the magnetic field strength of the magnet D. the power supply voltage.
10. As shown in the figure, a pulley with a gravity of 400N is lifted by a pulley block at a uniform speed of 6m, and the pulling force F used is 250N, so the mechanical efficiency of the pulley block is
A.60% B.70% C.80% D.90%
5. Fill in the blanks (65438+ 0 points per grid, ***20 points)
26. In order to determine the density of milk, a bag of milk was poured into a beaker, and the total mass of milk and beaker was measured to be 320g g.. Then pour some milk into the measuring cylinder, and the number of the measuring cylinder is shown in the figure. When the total mass of surplus milk and beaker is 254g, the mass of milk in the measuring cylinder is ▲ g, the volume is ▲ mL, and the density of milk is ▲ g/cm3.
27. As shown in the figure, put a piece of wood weighing 5N into a beaker. When the wood is at rest, the buoyancy is ▲ N and the direction is ▲. After wood is put in, the water pressure at the bottom of the beaker is higher than before ▲ (fill in "bigger", "smaller" or "unchanged").
28. The calorific value of hydrogen is 14.3× 107J/kg. When 0. 1kg hydrogen is completely burned, it can release the heat of ▲ J, which can raise the temperature of 100kg water from 20℃ to ▲℃. As a fuel, the product of hydrogen combustion is only water, which has the characteristics of ▲ compared with coal.
29. As shown in the figure, it is the circuit diagram of the household refrigerator. The normal working voltage of the refrigerator is ▲ V. The compressor is connected with the lighting lamp. The function of compressor is to change gaseous refrigerant into liquid by pressurization.
In order to make use of solar energy, scientists have designed a kind of "solar pond", in which the lower layer is concentrated brine and the upper layer is fresh water. When the sun shines, the internal energy of concentrated brine will increase, but it will not float to fresh water to dissipate heat, because the accumulated internal energy of concentrated brine is greater than that of fresh water. The internal energy accumulated by concentrated brine can be converted into energy by generator.
3 1. As shown in the figure, A and B are two graphs (excluding air resistance) indicating the change of kinetic energy and gravitational potential energy with the height of pebbles thrown vertically upwards, where ▲ is the kinetic energy-height relationship graph, the maximum height of pebbles is ▲ m, and the mechanical energy of pebbles at the highest point is ▲ j. 。
32. The grand occasion of the Shanghai World Expo can be spread to all parts of the world by satellite. You can also use ▲ to spread around the world through light waves (lasers).
Solving intransitive verbs (4 points for 33 questions, 6 points for 34 and 35 questions, 8 points for 36 to 38 questions, * * 40 points. There should be a problem-solving process when solving 34 and 35 questions.
33. Draw as required
(1) As shown in Figure A, the suspension bridge installed on the ancient moat, please make the rope in the figure pull the arm of force F.
(2) As shown in Figure B, light AO is incident on the plane mirror. Please reflect light according to the law of light reflection.
34. The forklift lifts the goods with a mass of 200kg at a speed of 2m(g) within 10s at a uniform speed (g is 10N/kg). Find: (1) the gravity of the goods; (2) The power of the forklift to do work on the goods.
35. As shown in the figure, the power supply voltage is constant, and the resistance of R 1 is 20 Ω. Only when the switch S 1 is closed, the ammeter reads 0.3A；; When S 1 and S2 are closed, the ammeter reads 0.5A to find: (1) power supply voltage; (2) R2 power when S1and S2 are closed.
36. In the experiment of exploring the imaging law of convex lens.
(1) Let a beam of parallel light shine directly on the convex lens, and receive the smallest and brightest spot on the light screen behind the convex lens, thus bringing.
(2) When the candle, convex lens and light screen are placed as shown in the figure, a clear image is obtained on the light screen. At this time, the object distance is ▲ cm, and the image size is larger than the object size ▲.
(3) When the object distance is less than the focal length, the screen can't receive the image, which should be (▲).
A. move the light screen up and down to receive B. put the light screen on the left side of the convex lens to receive.
C. Remove the light shield and observe directly through the convex lens.
Xiao Ming wants to explore what factors are related to the speed of football rolling.
(1) Xiaoming thinks that it is difficult to ride fast without inflating bicycle tires, so he guesses that the more inflated the football is, the more it rolls.
(2) As shown in the picture, Xiao Ming did an experiment on a slope. He measured that the football was released at point A, and it took 8 s to roll 10m to point B; After releasing some air, the football needle is released from the static state at point B, and it takes 10m to reach point C, which is 14s. The measuring tools that Xiao Ming needs in the experiment are stopwatch and ▲.
(3) The average speed of football in AB segment is ▲ m/s. 。
(4) Xiaoming's experiment has some shortcomings. Please point out one thing: ▲.
38. Read the passage and answer the questions after it
When the cells of trees are damaged at low temperature, the resistance of branches will change. The cold tolerance of trees can be identified by electrical resistance measurement. In the experiment, some branches of a tree species with the same thickness and length were put into different freezers, frozen at different temperatures, and taken out after 24 hours. When they return to room temperature, measure the resistance between two points at the same distance. Some measured data of this tree species are shown in the following table.
Freezing temperature /℃ -40 -30 -20-10 0
Branch resistance/ω 21.127.2 ▲ 39.045.1
(1) As shown in Figure A, the circuit for measuring branch resistance is completed. Please connect the circuit with pressure wires, not wires.
(2) When measuring the branch resistance with freezing temperature of -20℃, the voltmeter reads 8.6V, and the current indicator is as shown in Figure B. Please calculate the resistance and fill it in the table.
(3) Draw the relationship between branch resistance and freezing temperature in Figure C. 。
(4) According to the image, the relationship between branch resistance and freezing temperature is▲.
Xuzhou 20 10 physics examination paper.
Reference answers and grading standards
A, multiple-choice questions (this topic *** 10 small questions, each 2 points, ***20 points)
The title is 1 23455 6789 10.
Answer A C D B D A C A B C
V. Fill in the blanks (this question is ***7 small questions, 65438+ 0 points per blank, ***20 points)
26.66 60 1. 1 27.5 (vertical) becomes larger upwards.
28.1.43x10754 No pollution (clean)
29.220 and liquefaction 30. Temperature density electricity
3 1.A4232。 Electromagnetic (micro) optical fiber (optical cable)
Six, answer the question (this question ***6 small questions, ***40 points)
33. For each small question, 2 points, ***4 points. The answer is shown below.
33 questions scoring instructions:
(1) The arm of force in Figure A is obviously not perpendicular to the line of action of force, so it does not score.
(2) In Figure B, the normal line 1, the reflection angle is equal to the incident angle 1 and the arrow 1 until the buckle is finished.
34. This question ***6 points
Solution: (1) (3 points)
(2) ( 1)
(2 points)
35. This question ***6 points.
Solution: (1) (3 points)
(2) ( 1)
(2 points)
Scoring instructions for questions 34 and 35:
(1) There is no calculation process in the solution, only the final answer is not scored.
(2) If the problem solving method is correct, but it is different from the reference answer, you can refer to the grading standard and give points accordingly.
36. This question is ***8 points.
(1) focal length (2 points)
(2) 15 (2 points for each space, ***4 points)
(3)C (2 points)
37. This question is ***8 points.
(1) Fast (2 points)
(2) Scale (2 points)
(3) 1.25 (2 points)
(4) The football is not released from the same position (there is no control variable; Without repeated experiments) (2 points)
38. This question ***8 points.
(1) As shown in Figure A, each conductor is 1. (2 points)
(2) 33.1(33,33.08) (2 points)
(3) As shown in Figure C (2 points, where 1 point is the correct trace and 1 point is a straight line)
(4) The higher the freezing temperature, the greater the branch resistance (the lower the freezing temperature, the smaller the branch resistance; There is a linear relationship between branch resistance and freezing temperature) (2 points)