Exam paper for the final exam of the first volume of Grade 8 physics

1. Multiple-choice questions (single choice, 2 points for each question, ***3 points)

The question number is 1 2 3 4 5 6 7 8 9 1 11 12 13 14 15

Answer

1. But it landed on the moon, and even if the astronauts were nearby, they couldn't hear the sound. This is because ()

A. When the surface of the moon was hit, it didn't make any sound. B. The impact sound was too small for human ears to hear.

C. There was no air on the surface of the moon, so the sound couldn't spread. D. When it hit the moon, it produced ultrasonic waves.

2. Here are some vibrating objects: A: The arm waved up and down once per second. B: The bat's mouth vibrates at a frequency of 15Hz; C: When you hit the tuning fork with a small hammer, it vibrates at 256Hz. The following statement is correct: ()

A. We can only hear the sound from the tuning fork, so C is the sound source, and others are not

B. A, B and C are all sound sources, and we can all hear their sounds

C. A, B and C are all sound sources, and we can only hear C. B is not a sound source, because we can neither see vibration nor hear sound

3. The following statement about sound is incorrect ()

A. As the saying goes, "Sound insulation has ears", It shows that solids can also transmit sound

B. "deafening" mainly shows that the tone of sound is high

C. "You can tell a person by his sound" mainly depends on the timbre

D. Sound cannot transmit in vacuum

4. The following statements are incorrect: ()

A. Mirror reflection obeys the law of light reflection

B. It is still a parallel beam

C. Diffuse reflection does not follow the reflection law of light

D. After the incident parallel beam in diffuse reflection is reflected, It is no longer a parallel beam

5. Which of the following situations is the image observed by periscope ()

A. An upright reduced real image B. An upright isometric real image

C. An inverted magnified virtual image D. An upright isometric virtual image

6. Which of the following statements is true ()

A. The moon is huge. It is 34m/s

C. The shadow is formed due to the straight-line propagation of light

D. Diffuse reflection does not obey the law of light reflection

7. The following statement is correct ()

A. The monkey sees the "moon" in the water, and the distance from the "moon" in the water to the water surface is equal to the depth of the water in the well

B. When taking pictures with a camera, If you want to see the nuances on the stamp clearly, the distance between the magnifying glass and the stamp should be equal to 1cm.

8. The following statement about the imaging problem is incorrect: ()

A. You can get an inverted image by using a pinhole camera

B. Standing on the shore, you can see objects in the water, which are actually virtual images of objects

C. Sometimes the photographer brings us closer to him to make the image in the negative bigger

D. A flat mirror can make the room look more spacious. It is because the image is farther away from the mirror than the object

9. Regarding the imaging situation of the four optical instruments, the following statements are correct: ()

A. The magnifying glass becomes an upright and enlarged real image B. The camera becomes an upright and reduced real image

C. The slide projector becomes an inverted and enlarged real image D. The myopia glasses become an upright and enlarged virtual image

1. The following statement is correct: ()

A. Rain is formed by the liquefaction of water. B. Dew is formed by the vaporization of water.

C. Frost is formed by the condensation of water vapor. D. Fog is formed by the condensation of water vapor.

11. The following statement is correct: ()

A. In summer, the "white steam" of sorbet we see is a vaporization phenomenon < The frost on the hay is formed by water solidification.

C. The pressure cooker uses the boiling point of liquid to decrease with the increase of gas pressure above the liquid surface, so that food can be cooked easily.

D. The refrigerator uses the rapid evaporation of refrigerant to absorb heat, so that the temperature in the refrigerator is reduced.

12. In the room, draw a thermometer out of alcohol. Its indicator will be ()

A. It will always increase B. It will always decrease

C. It will increase first and then decrease D. It will decrease first and then increase

13. The following statement is correct: ()

A. Rubber, plastic, glass, water and air are insulators

B. Insulators can't conduct electricity because they have no electrons inside

. Aqueous solutions of alkali and salt can conduct electricity

D. Pure water is a conductor, because water can be electrolyzed

14. The following statement is correct ()

A. The measuring range of ammeter is its measuring range

B. When using ammeter, the larger the range, the better

C. If the measuring range of ammeter cannot be determined, choose the terminal with the minimum range to try to touch it < You can connect the ammeter directly to the two poles of the power supply

15. Xiao Ming found that the road light in the school corridor lights up when it is dark at night, but it doesn't light up no matter how hard you clap your hands during the day. Later, the teacher told Xiao Ming that the road light is controlled by both light control and voice control switch, in which the light control switch is turned off when it is illuminated and the voice control switch is turned on when it receives sound. So what do you think is the correct connection of the corridor room as shown in the figure ()

2. Fill in the questions (1 point for each space, ***41 points)

1. Donglin College's famous association "Wind, rain, reading, sound in the ear" shows that sound can spread in the classroom; When playing the music "Two Springs Reflecting the Moon" with violin and erhu, we can distinguish it according to the different sounds.

2. There is a concert in the concert hall. The baritone is singing loudly, the soprano is singing softly, and there are many musical instruments to accompany it. At this time, the baritone is bigger than the soprano, while the soprano is higher than the baritone. The sound of the concert sounds rich in three dimensions, which is mainly due to the effect of human hearing.

3. In order to remind people not to forget the national humiliation and to be alert to the rise of Japanese imperialist forces, on the occasion of the 5th anniversary of the Nanjing Massacre, Nanjing citizens donated money to cast the Jingshizhong, which is 3m high and 2m in diameter. When the clock is hit with a wooden stick, its vibration amplitude (fill in "very big" or "very small") and vibration frequency can make a loud and low sound.

4. Due to the phenomenon of light, students in different positions in the classroom can see the chalk characters on the blackboard. (Fill in "diffuse reflection" or "specular reflection")

5. After passing through the prism, sunlight is decomposed into various colors, which is a light phenomenon. Three colors of light can be mixed properly to produce other colors of light, which are red light and blue light respectively.

6. the angle between the incident light and the plane mirror is 6? , then the reflection angle is that someone stands 1m in front of the mirror, and the distance from his image in the mirror to him is m..

7. The calf has a convex lens with a focal length of 5cm. If you want to use it as a model camera, the distance from the scene to the convex lens should be; If you want to use it as the lens of the projector, the distance from the film to the convex lens should be; If you want to use it as a magnifying glass, the distance between the observed object and the convex lens should be.

8. As shown in the picture, please answer the following questions

(1) The optical instrument used in the picture is a lens. The reason why an enlarged image can be formed is that when the object is away from the lens, it forms a vertical and vertical < P > image.

(2) Xiaoming pointed this lens towards the sun and found a tiny bright spot at the other side of the lens, which is 5cm away from the lens. Then, if Xiaoming wants to use this lens to get a reduced image, he should put the object at a distance from the lens.

(3) Xiaoming uses this lens to study the imaging law of the lens. In the experiment, the lens should be placed in front of the candle and the light screen, and their height and position should be adjusted so that their centers are roughly on the floor.

9. as shown in the figure, it is the schematic diagram of the experiment of "studying convex lens imaging". If a clear and enlarged real image of candle flame can be obtained on the light screen (the light screen is not drawn), the candle may be placed at the four points A, B, C and D on the left side of the lens, and this imaging feature can be applied to the world.

1. Among the following phenomena of state change, the one that belongs to solidification is; What belongs to sublimation is; Among them, ② ③ ⑤ is (fill in "exothermic" or "endothermic") process.

① The wet clothes hanging outside are dry.

② In summer, when the wrapping paper of popsicles is unwrapped, popsicles will emit "white 37m"

③ In winter, there is a layer of ice on the river

④ The mothballs put in the wardrobe will become smaller and smaller, and finally "disappear"

⑤ In the dead of winter, there is a layer of ice flowers on the inner surface of classroom window glass

⑤ When paving asphalt roads, put asphalt blocks. He found that "cooking rice can't make a meal" on the mountain. He thought that the spring water on the mountain was too cold. In fact, this was due to the low temperature on the mountain, which led to the boiling point of water.

12. When dry ice (solid CO2) is exposed to normal temperature, it will directly change from solid to gas. This phenomenon is called the faint white fog produced on the stage by dry ice, which is caused by the cooling of the surrounding air and the formation of water vapor in the air when it meets cold.

13. The glass rod rubs against the silk, and the glass rod is electrified, and the silk is electrified, because the glass rod is lost and the silk is gained during the rubbing process.

14. In the circuit as shown in the figure, the switch S is always closed. To connect the small bulbs L1 and L2 in series, the switch must be closed. To connect L1 and L2 in parallel, the switch must be closed. If the switch is closed, it will cause a short circuit.

15. A group of colored lights used for festivals is connected with 2 small bulbs. It is known that the current at the plug is 15mA, so the current between the eighth and ninth small bulbs is A, and the current passing through the twentieth small bulb is A..

3. Drawing questions (1 points)

1. Make the images generated by △A, B and C in the plane mirror (2 points)

2. As shown in the figure, S is the luminous point, Sˊ is the image of S in the plane mirror, and the reflected light of a human ray emitted by S is in the AB direction. Please draw the plane mirror in the figure. (2 points)

s ●

●

s'

3. There is a lens in each box as shown in the figure, which shows the propagation direction of light before and after passing through the lens. Please fill in the appropriate lens in the box. (4 points)

A B C D

4. Complete the optical path diagram in the drawing. (2 points)

IV. Comprehensive questions (19 points)

1. As shown in the figure, what will happen if water vapor comes out of a glass tube and is sprayed on another flask filled with cold water? Has the temperature of cold water in the flask changed after a normal time? What problems can this experiment be used to explore? (5 points)

2. Draw the circuit diagram according to the physical picture, and answer the question: When the switch is closed, the indicators of A and B ammeters are as shown in the figure, then the current flowing through A lamp, B lamp and main road is A.. (5 points) < P > 3. (1) As shown in the picture, what is the vision problem of this eye?

(2) What lens should I wear to correct this eye? Why do you do this to make your eyes see things clearly? (4 points)

4. Someone was standing by the railway and saw the railway maintenance worker knocking on the rail with a small hammer in the distance. He was close to the rail and heard two knocks after a while. If the interval between two sounds is .5s, and the person is 183.6m away from the percussion, what is the speed of sound propagation in the rail? (It is known that the speed of sound propagation in the air is 34m/s)(5 points)

First semester of Xingyi No.5 Middle School in 27-28

Answers to the eighth grade physics test paper

1. Multiple choice questions (2 points for each question, ***3 points)

The question number is 1 2 3 4 5 6 7 8 9 1 11 12 13 14 15

The answer is CCB, CCD, CCD, CCD, CCD, CCD

2. Fill in the blanks

1. Air, timbre 2, loudness, tone, ears 3, very big and very small

4. 2

7, more than 1cm, more than 5cm less than 1cm, less than 5cm

8, (1) convex, less than, focal length, positive, magnified, imaginary (2) more than 1cm (3) middle, same height

9, c, slide projector, etc. 1, ③, ④. 11, air pressure, low

12, sublimation, sublimation and heat absorption, liquefaction, water droplets 13, positive and negative, electrons, electrons

14, S2, S1S3, S1S2S.