Review outline of physics midterm in the first volume of the second day of junior high school

1. Choose carefully (3 points × 12 = 36 points)

1. Measure the diameter of the thin copper wire tightly wound on the pencil, as shown in figure 1. The following statement is correct ().

A. the dividing value of the scale used is 1cm.

B when reading the scale in the drawing, the line of sight should be parallel to the scale surface.

C. The total length of the coil in the drawing is 15cm.

D. The number of turns of the winding coil needs to be counted in the experiment.

2. When imaging with a convex lens, the following statement is correct ().

A. the real image is always upside down, and the virtual image is always upright.

B. Both the real image and the virtual image can be enlarged or reduced.

C when the real image is formed, the closer the object is to the convex lens, the smaller the image is.

D. When a virtual image is formed, the closer the object is to the convex lens, the larger the image is.

3. China vigorously develops thermal power generation. When coal enters the thermal power station, electricity is generated. In this process, the energy conversion is ().

A. mechanical energy → internal energy → chemical energy → electric energy B. chemical energy → internal energy → mechanical energy → electric energy

C. chemical energy → gravitational potential energy → kinetic energy → electric energy D. internal energy → chemical energy → mechanical energy → electric energy

4. About real image and virtual image, the following statement is true ()

A. the light curtain can collect real images, but not virtual images.

B. Virtual image is an illusion of people. No light enters the human eye, but the real image is the opposite.

C the real image must be formed by the refraction of light, and the virtual image must be formed by the reflection of light.

D. the real image is enlarged and reduced, and the virtual image is all enlarged.

On the playground, physical education class always feels that the teacher's voice doesn't sound loud in the classroom. The following statement is wrong.

( )

A. The human ear rarely hears echoes with a difference of less than 0. 1s from the original sound.

The PE teacher's voice is too small.

C. outside, the teacher's voice is passed around, and there is almost no response.

D. When talking indoors, the echo is mixed with the original sound to strengthen the original sound.

6. Put a coin in an empty teacup, just out of sight (as shown in Figure 2). Keep the eyes and the cup in the same position and slowly fill the cup with water. The following statement is correct ().

A. With the increase of water, the eyes can see coins, but the position is higher than the actual position.

B. With the increase of water, the eyes can see coins, but the position is lower than the actual position.

C with the increase of water, the eyes can see the coin, and the position has not changed.

D. coins are still invisible after water injection.

7. Xiaohong sticks his ear to one end of a long iron pipe, and Xiaoming knocks on the other end. Xiaohong heard the noise twice. This is because ()

A. there is an echo

B. Refraction of sound

Sound travels faster in air than in iron.

Sound travels faster in iron than in air.

8. As shown in Figure 3, four identical glass bottles contain water with different water levels. When blowing into the bottle mouth, the sound difference is ().

A. Ding bottle has the highest tone and different tones.

B. Different tones, bottle C has the highest tone.

C. the same sound c bottle has the loudest loudness.

D. the loudness of the homodyne ding bottle is the largest.

9. It often happens that cats and dogs have pricked up their ears and listened warily when people are unaware of it. This is because ()

A. cats and dogs are smarter than people.

B cats and dogs can hear high-frequency sounds that people can't hear.

C. cats and dogs have a wider range of vocal frequencies than people.

D. People's listening frequency range is wider than that of cats and dogs.

10. Which of the following phenomena is not a proliferation phenomenon ()

A. The sanitary ball was put in the box, and within a few days the box was full of camphor smell.

B. put a piece of sugar in a glass of water, and the water will become sweet after a while.

C. Sprinklers spray water on the ground.

D. The coal piled in the corner for a long time dyed the wall black.

1 1. As shown in Figure 4, there is a flat mirror on the horizontal desktop, and a ball rolls towards the mirror on the desktop. To make the image of the ball fall vertically in the plane mirror, the angle between the mirror and the desktop should be ().

300 BC 450 BC 600 BC 900 AD.

12. In the experiment of studying plane mirror imaging, a candle was placed in front of and behind the vertical glass branch. Facing the glass plate, you can see the image of the candle in front and the candle in the back behind the glass plate. The following statement is correct ().

A. The former is an image formed by light reflection, and the latter is an image formed by light refraction.

B The former is an image formed by light refraction, and the latter is an image formed by light reflection.

C. both are images formed by light reflection.

D. Both of them are images formed by light refraction.

2. Fill in patiently (3 points× 7 = 21minute)

13. There are the following optical phenomena: ① hand shadow, ② mirage, ③ reflection, ④ eclipse, ⑤ movie, ⑤ monkey fishing for the moon, ⑤ looking in the mirror, and ⑧ photography. The above optical phenomena can be divided into three categories:

One category includes: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _, and its * * feature is _ _ _ _ _ _ _ _ _ _ _.

The second category includes: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _, and its * * * feature is _ _ _ _ _ _ _ _ _ _ _.

These three categories include: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

14. As shown in Figure 5, two tuning forks with the same frequency have opposite open ends and are arranged side by side at a certain distance. Tap the right tuning fork with a rubber hammer to make it sound, and then press the rubber hammer on the tuning fork to stop it from vibrating. Observe carefully and find the tuning fork _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

15. As shown in Figure 6, the scale value of the thermometer is _ _ _ _ _. Please read the thermometer below, the reading is.

16. As shown in Figure 7, measure the average thickness of a piece of paper with a scale. The total thickness of a book is _ _ _ _ cm, and the book * * * has 250 pages, so the average thickness of a piece of paper is _ _ _ _ _ cm.

17. As shown in Figure 8, it is a schematic diagram drawn according to the photos of the clock hung in a hotel in Beihai, Guangxi. In the picture, the second hand, minute hand and dial marked with 24 numbers all rotate clockwise. According to the instructions of the clock, this photo was taken at _ _ _ _ _ _ _ _ _ _ Beijing time (according to the 24-hour clock).

18. Xiaoli can increase the loudness of sound by the following methods when exploring the loudness of objects. Please tell me the reason:

(1) Insert the tuning fork into the empty * * * box: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

(2) When speaking, put your hands on your mouth like horns: _ _ _ _ _ _ _ _ _ _ _.

(3) Put the watch to your ear, and the sound is very weak. Put the watch in a large porcelain bowl, and the sound will be very clear: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

19. Write the following energy conversion: when the motor rotates at high speed after being electrified, the _ _ _ _ energy is converted into _ _ _ _ _ _ _ energy; After the car brakes, it leaves two black scratches on the cement floor, which is the conversion of _ _ _ _ energy into _ _ _ _ _ energy; Fuel combustion produces light and heat, which can be converted into _ _ _ _ _ energy and _ _ _ _ _ energy.

Three. Scientific inquiry (5 points +6 points +6 points = 17 points)

20. When doing the experiment of "Studying the Characteristics of Sound", Xiaoli has the following experimental steps (as shown in Figure 9).

(1) Press a steel ruler tightly on the desktop, with one end sticking out of the edge of the desktop 10cm. Move the steel ruler and listen to the sound it makes when it vibrates.

(2) Make one end of the steel ruler extend out of the edge of the table 15cm, stir the steel ruler to keep the same vibration amplitude as the steel ruler in (1), and listen to the sound when it vibrates.

(3) Make one end of the steel rule extend out of the table 15cm, increase the vibration amplitude of the steel rule, and listen to the sound when it vibrates.

Please fill in the following table to describe the phenomena and feelings of the experiment:

The length of the steel rule protruding from the edge of the table.

Vibration intensity

oscillating frequency

volume

hue

10cm

15cm

15cm

The above experiments show that: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

2 1. Students in a physics extracurricular activity group in a school know that the speed of light propagation in water is 3/4 of that in vacuum, and that in glass is 2/3 of that in vacuum. The following are the relevant data measured by the students in this group through experiments.

Table 1 light inclines from the air into the water meter 2. Light inclines from the glass into the air.

Number of experiments

Angle of reflection

refraction angle

Number of experiments

Angle of reflection

refraction angle

1

200

14. 10

1

200

3 1.20

2

300

19.30

2

300

44.50

three

celebrity

24.50

three

celebrity

56.30

By analyzing the data in the table, we can draw the following conclusions:

( 1)___________________________________________.

(2)___________________________________________.

(3)___________________________________________.

1. Xiaoming uses the device shown in figure 10 to explore the reflection law of light on the plane. M is a small flat mirror, and E and F are two pieces of cardboard, which can rotate back and forth around ON. In the experiment, the laser beam emitted by the laser is obliquely incident on the M plane mirror along the surface of the cardboard E perpendicular to the mirror surface, and the incident angle and reflection angle are measured with a protractor. The measured data are shown in the following table. Xiao Ming also found in the experiment that when F cardboard is turned back and forth around ON, no reflected light can be observed, but when E and F are on the same plane, only reflected light can be observed.

Number of experiments

Angle of reflection

Angle of reflection

1

300

300

2

450

450

three

600

600

By analyzing the phenomena observed in Xiao Ming's experiment and the data recorded in the experiment, we can draw the following conclusions:

( 1)________________________________________.

(2)________________________________________.

(3)________________________________________.

4. Physics in life (5+6 = 1 1)

2. Spread a piece of white paper on the desktop at night, and put a small flat mirror on the paper, so that the light of the flashlight can directly shine on the flat mirror, as shown in figure 1 1. Seen from the side, the white paper is bright, while the flat mirror is dark. Do and explain why?

With the rapid development of the world economy and the continuous expansion of human activities, the total amount of energy consumed by human beings is accelerating. However, the total amount of energy provided by nature such as coal, oil and natural gas is limited, and oil and natural gas resources will soon be exhausted. Moreover, the extensive use of these energy sources will pollute the environment and lead to the deterioration of climate and ecology. In order to achieve sustainable development, human society must find and develop new energy sources. As a middle school student in the new era, please talk about the ideal energy in the future.

Verb (abbreviation of verb) is innovative in application (5 points× 3 =15 points)

4. As shown in figure 12, S is the light source in front of the plane mirror, and A is the point in front of the plane mirror. Now, the light beam emitted from the point light source S is reflected by the plane mirror and passes through the point A to try its optical path.

5. As shown in figure 13, S is the light-emitting point, and the two rays reflected from it coincide with the dotted lines A and B respectively after being reflected by the plane mirror. According to the imaging law of plane mirror, the image S' of plane mirror and point light source S is drawn.

6. Try to draw a picture to show that people standing on the shore see the image of fish in the water as _ _ _ _ (fill in "shallow" or "deep"). (as shown in figure 14)

Mid-term exam B

1.D 2。 A 3。 B 4。 A 5。 A six. A seven. D 8。 A nine. B 10。 C 1 1。 B 12。 A

13. Category I: ① ④, which is related to the straight-line propagation of light; The second category: ③ ⑤ ⑤, which is related to the reflection of light; The third category: ② ⑤ ⑧, related to the refraction of light.

14. Sound; Small ball; * * * Ming15.0.1℃; 38.9℃ 16. 1.20; 0.0096 17.20; 24; 57

18.( 1) Use the sound of * * * (2) to increase the loudness, reduce the dispersion of the sound and increase the loudness of the sound;

(3) Using echo to strengthen the original sound and increase the loudness of the sound.

19. Electricity; Machinery; Machinery; Inside; Chemistry; Light; inside

20.

The length of the steel rule protruding from the edge of the table.

Vibration intensity

oscillating frequency

volume

hue

10cm

small

high

small

high

15cm

small

low

small

low

15cm

big

low

big

low

Loudness is related to amplitude, and the greater the amplitude, the greater the loudness; Tone is related to the frequency of vibration. The higher the vibration frequency, the higher the pitch.

When 2 1.( 1) light refracts, the refraction angle increases with the increase of incident angle. (2) When light is obliquely incident from air into water, the refraction angle is smaller than the incident angle. (3) When the light obliquely enters the air from the glass, the refraction angle is greater than the incident angle.

22.( 1) When light is reflected, the reflection angle is equal to the incident angle. (2) The reflected light and the incident light are separated on both sides of the normal.

(3) Reflected light, incident light and normal line are in the same plane.

23. When the light hits the flat mirror, a specular reflection occurs, and the reflected light is upward, and no reflected light enters the eyes on the side, so the eyes feel that the flat mirror is relatively dark; What happens on the paper is diffuse reflection, and there is always reflected light that can enter the eyes on the side, so I see that the white paper is illuminated.

24. The ideal energy in the future must meet four conditions: first, it must be rich enough to ensure long-term use; Second, it must be cheap enough to ensure that most people can afford it; Third, relevant technologies must be mature and can ensure large-scale use; Fourth, it must be safe and clean enough to ensure that it will not seriously affect the environment.

25. As shown in Figure 26. As shown in fig. 27. Shallow; As shown in the figure

This information is provided by Colorful Education Network!

Close prompt close

Confirmation, cancellation and cancellation