The convex lens imaging law exercises examination questions. The eighth grade physics test paper has the answer.

1. When the distance from the object to the convex lens is _ _ _ _ _ _ _, it becomes an inverted image and a reduced image; When the distance from the object to the convex lens is equal to twice the focal length, the distance from the image to the convex lens is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

2. When the distance from the object to the convex lens is _ _ _ _ _ _ _, it becomes an inverted magnified real image; When the distance from the object to the convex lens is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ When the distance from the object to the convex lens is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _, it becomes an upright magnified virtual image.

3. The camera is made according to the optical principle that a convex lens can form an image of _ _ _ _ _ _ _ _. The focusing device of the camera is used to adjust the distance from the lens to _ _ _ _ _ _ _ _ _. When shooting a close shot, the lens should be moved forward, and there is a distance from the film _ _ _ _ _ _ _ _ _ _ _. The aperture is used to control the entrance of the lens. The shutter is used to control the exposure of _ _ _ _ _ _ _.

4. The projector is made according to the optical principle that the convex lens can form an image of _ _ _ _ _ _ _. When projecting, the picture on the screen is too small for students to see clearly, so it needs to be enlarged. The adjustment method is to adjust the lens to _ _ _ _ _ _ _ (fill in "up" or "down"), and the projector and students can't see it clearly at the same time.

1 is more than twice the focal length, equal to twice the focal length, equal to.

More than one focal length but less than two focal lengths, and one focal length is less than one focal length.

30% inversion reduces the foreground size of the real scene.

The inverted magnification of the virtual image is much lower than that of the virtual image.

First, fill in the questions.

1. Among convex mirrors, concave mirror, convex lenses and flat mirrors, _ _ _ _ mirrors can condense light.

2. There is a convex lens with a focal length f. If the candle flame is placed outside the convex lens 2f, a _ _ _ _ _ _ _ _ _ real image will be formed on the _ _ _ _ surface of the convex lens, and an optical device _ _ _ _ _ will be made by using this rule.

3. Pinhole imaging is due to the image of light, flat mirror imaging is due to the image of light, and lens imaging is due to the image of light.

4. Using convex lens can not only _ _ _ _ light, but also image. This image, which is formed by _ _ _ light and can be displayed on the screen, is called a real image.

Second, in the experiment of studying the imaging law of convex lens, judge whether the following conclusions are correct.

1. The focal length of the convex lens used in the experiment must be known. ( )

2. The order of equipment on the light stage is candle flame, convex lens and light screen. ( )

3. The distance from the object to the convex lens is called the object distance, which is expressed by U ... ()

4. The distance from the image to the convex lens is called the image distance, which is expressed by v. ().

5. The distance from the focal point to the optical center of the convex lens is called the focal length, which is denoted by f ... ()

6. Virtual images cannot be formed on the screen. ( )

7. The real image is upside down and the virtual image is upright. ( )

8. Before the experiment, adjust the height of the candle, light screen and convex lens so that their centers are roughly at the same height. ( )

Third, multiple choice questions

1. The following statement is true [] A. A convex lens must be a real image B. A convex lens must be a virtual image C. A convex lens must be like D. A convex lens can be a virtual image.

2. It is known that the focal length of the convex lens is 10 cm and the distance from the object to the convex lens is 15 cm, so the image is [].

A. the true image of reverse reduction

B. Inverted enlarged real image

C. Vertical miniature image

D. upright enlarged image

Convex lens imaging and its application Group A answers:

I. 1. Convex infiltration

2. another one; Reduce handstands; camera

3. Straight-line propagation; Reflection; optometry

4. refraction; reality

Two. 1.√ 2.√ 3.× 4.× 5.√ 6.√ 7.√ 8.

Three. 1.D2

Compilation of Examination Questions in 2006 (Lens and Its Application)

First, multiple-choice questions:

(Hebei, 2006) When exploring the law of convex lens imaging, Xiao Ming kept the position of convex lens unchanged, put candles at four points A, B, C and D, and adjusted the position of light screen respectively, as shown in Figure 2. After exploration, he summed up the following statement. The correct one is (a)

A. the camera is made by using the imaging characteristics of the candle placed at point a.

B the magnifying glass is made by using the imaging characteristics of the candle placed at point B.

C. the slide projector is made by using the imaging characteristics of candles placed at point D.

D. the image of the candle at point b is bigger than that at point C.

(Pudong, Shanghai, 2006) A classmate did a convex lens imaging experiment. When the screen is 0/2 cm away from the convex lens/kloc-,he finds a clear and reduced image on the screen, from which it can be judged that the focal length of the convex lens may be (b).

A.5cm cm B.10cm C.15cm D.20cm.

(Jiangxi, 2006) has three convex lenses with a focal length of 20cm. Xiao Ming made some simple optical equipment with them. The first one made a simple camera and took a picture on the wall. The second one is made into a projector to demonstrate slides. The third is to observe a small insect directly as a magnifying glass. In use, the following correspondence is correctly connected (C)

(Chaoyang District, Beijing, 2006) The focal length of the convex lens is 12cm. When the object is placed on the main shaft 7cm away from the lens center, the image formed by the object is (C).

A. Inverted and reduced real images

B. Inverted and enlarged real image

C. Vertical and magnified virtual images

D. vertical and equal virtual images

Linyi City (2006) Li Ming's mother found that after entering junior high school, Li Ming studied harder than before, but she also found that when reading, the distance between eyes and books was getting closer than usual. Please choose the correct one from the following judgments and corrective measures to explain to Li Ming (b).

A. Li Ming is nearsighted and needs to wear glasses made of convex lenses.

B: Li Ming is nearsighted and needs to wear glasses with concave lenses.

C Li Ming suffers from hyperopia and needs to wear glasses made of convex lenses.

D Li Ming suffers from hyperopia and needs to wear glasses made of concave lenses.

(Xiamen, 2006) In the experiment of "studying the imaging law of convex lens", the following statement is correct: (c)

A, the order of equipment on the light stage is candle, light screen and convex lens.

B. Virtual images can also be formed on the screen.

C, become a real image, the object distance decreases, the image distance increases, and the image becomes larger.

D, adjust the height of the candle, light screen and convex lens before the experiment, so that their centers are in a straight line.

(Foshan in 2006) (c)

(Guangzhou Haizhu, 2006) When the candle is placed 40 cm away from the main optical axis of the convex lens, a clear and enlarged image is obtained on the screen on the other side of the lens. If the candle is 40 cm away from the lens in its original position, the clear image will be (D).

A. Virtual image B. Enlarge C. Stand upright D. Reduce

(Hebei, 2006) When exploring the law of convex lens imaging, Xiao Ming kept the position of convex lens unchanged, put candles at four points A, B, C and D, and adjusted the position of light screen respectively, as shown in Figure 2. After exploration, he summed up the following statement. The correct one is (a)

A. the camera is made by using the imaging characteristics of the candle placed at point a.

B the magnifying glass is made by using the imaging characteristics of the candle placed at point B.

C. the slide projector is made by using the imaging characteristics of candles placed at point D.

D. the image of the candle at point b is bigger than that at point C.

Yichang (2006) An object can form an inverted magnified real image on the light screen through a convex lens. Which of the following optical instruments applies this imaging principle (C)?

A. camera B. magnifying glass C. slide projector D. car rearview mirror

(Hengyang, 2006) The human eye is like a camera, and the interaction between lens and cornea is equivalent to a convex lens. When people observe an object, the image of the object on the retina is (a)

A. Inverted and reduced real image B. Inverted and enlarged real image

C. Vertical magnified virtual image D. Vertical magnified real image

(Zhuzhou, 2006) The remote controller of TV can emit a kind of invisible light called infrared ray, which can be used to control TV. Sometimes the remote controller is not aimed at the control window of the TV, but at the wall in a suitable direction to press the button, which can also control the TV. This uses (a)

A. reflection of light B. refraction of light C. straight-line propagation of light D. high speed of light

(Taiyuan, 2006) The human eye is like a camera. The light emitted by the object is refracted by the lens and imaged on the retina. The image on the retina is (b).

A. Inverted magnified real image

C. vertically enlarge the virtual image D. vertically reduce the virtual image

(Zhenjiang, 2006) The common visual defects are myopia and hyperopia. The picture on the right shows the schematic diagram of eyeball imaging for visually impaired people. The type of his vision defect and the type of glasses he needs to wear to correct his vision are (A)

A. hyperopia, convex lens B. hyperopia, concave lens

C. myopia, convex lens D. myopia, concave lens

(Zhenjiang, 2006) The focal length of convex lens is 10cm. When the lighted candle is moved from 50cm away from the convex lens to 15cm, the change of image size and image distance is (b).

A. the image becomes larger and the image distance becomes smaller. B. the image becomes larger and the image distance becomes larger.

C. the image becomes smaller and the image distance becomes smaller. D. the image becomes smaller and the image distance becomes larger.

(Xuzhou, 2006) Among the following optical instruments, the one that does not belong to convex lens application is (C)

A. Magnifier B. Myopic glasses C. Camera D. Microscope

(Yan Cheng, 2006) In the following optical diagram, the correct one is (a).

(Jinzhou, 2006) The following statement is correct (A)

A. the lens of the projector is equivalent to a convex lens.

B myopia requires glasses made of convex lenses.

C when looking at a map with a magnifying glass, the distance from the magnifying glass to the map is greater than the focal length.

D. The human eye is equivalent to a camera, and objects can form an upright and reduced real image on the retina.

Shenyang (2006) A In a sunny classroom, Xiaoyang moves between the white wall and the window with a convex lens with a focal length of 10cm, and can see the image of the window on the wall. This image is (b).

A. inversion, equal size b inversion, reduction

C. stand upright, zoom in D. stand upright, zoom out

(Chengdu, 2006) Regarding the imaging situation of four kinds of optical instruments, the following statement is correct (C).

A. The magnifying glass becomes an upright and magnified real image.

B. Take photos, and form a positive and restored real image with the machine.

C, the slide projector becomes an inverted magnified real image.

D. The nearsighted glasses became an upright and magnified virtual image.

(Chengdu, 2006) The focal length of a camera lens is 10cm. Xiao Gang used it to shoot his own small production. When the camera moves the work from 50 cm to 12 cm (a)

A. As the image becomes larger, the image distance becomes larger.

B. the image becomes larger and the image distance becomes smaller.

C. The image becomes smaller first and then larger, and the image distance becomes larger.

D. The image becomes smaller first and then larger, and the image distance becomes smaller.

Second, fill in the blanks:

(Inner Mongolia, 2006) The following picture shows the experiment of "Exploring the imaging law of convex lens". The focal length of the convex lens used is 10cm, and the position of the convex lens is fixed in the experiment. When the light screen has a focal length of 1.5 times, there is an image on the screen. Do you think that when the position of the light screen moves at least cm on the straight CD, there will be no image when the candle screen moves at will?

Answer: 5

(Beijing, 2006) The propagation direction of a beam of parallel light refracted by a convex lens is shown in figure 16A, from which it can be seen that the focal length of this lens is cm; When the candle flame is placed on the left side of the convex lens 12cm, as shown in figure 16b, an enlarged virtual image can be seen through the lens from the right side of the convex lens (fill in "positive" or "negative").

Answer:15 cm; ; just

Wuhu (2006) The lens in the human eye structure is equivalent to a mirror, and the light emitted by the object forms a reduced image on the retina through the lens (optional "positive" or "negative"). The clearest distance for human eyes to observe an object without fatigue is called apparent distance. According to the structure of presbyopia, the apparent distance of presbyopia (choose "greater than", "equal to" or "less than") is normal.

Answer: convex lens, inverted, greater than

Heilongjiang (2006) It is absolutely forbidden to throw away transparent beverage bottles anywhere in the forest. This is because the rainwater is equivalent to a _ _ _ _ _ _ _ mirror after entering the beverage bottle, which has _ _ _ _ _ _ _ _ _ effect on sunlight and may lead to forest fires.

Answer: Convex convergence

(Qinzhou City, 2006) The lens of a camera is equivalent to a lens (choose "convex" or "concave"); When you look at stamps with a magnifying glass (as shown in Figure 8), you will see an enlarged image (fill in "real" or "imaginary").

Answer: convex; empty

(Guilin, 2006) Once, when Xiao Ming was doing his homework at home, a drop of water fell on the glass table of his desk. Looking through the water drops, he found that the words on the animated picture pressed under the table became bigger. This is because the water drop is equivalent to one at this time, and the characters on the screen are refracted by the water drop to form an enlarged image (choose "real" or "virtual").

Answer: convex lens, virtual.

Yichang (2006) microscope has two groups of lenses at both ends, and each group of lenses is equivalent to one lens. When human eyes observe tiny objects through a microscope, they see magnified images (full of emptiness or reality).

Answer: convex; Virtual.

(Huanggang, 2006) In sports, researchers often use stroboscopic photography to analyze and guide athletes' movements. Stroboscopic photography is that when the photographic light source flashes rhythmically, the light emitted by the light source shines on the athletes, and _ _ _ _ _ _ _ _ _ _.

And through the _ _ _ _ _ mirror in front of the camera.

Form _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

For example. Looking at the photos in the picture, you can know the stroboscopic.

The background is required to be _ _ _ _ _ _ _ _ when shooting.

(Fill in "light" and "dark").

Answer: reflection; Convex lens; Inverted and reduced real image; dark

(Xiangfan, 2006) The fish fed in the round fish tank looks bigger than the real fish, because the round fish tank is equivalent to a mirror.

Answer: convex.

(Changsha, 2006) As shown in the figure, a beam of parallel light passes through a lens, and it can be seen from the figure that the lens is a _ _ _ _ _ _ _ _ _ lens. When it is used as the lens of a camera, when the object is placed beyond the focal length of 2 times, it can become an inverted reduced image of _ _ _ _ _ _ _.

Answer: convex; solid

(Zhuzhou, 2006) The eyes are the windows to the soul. As shown in figure 1, this is the optical path diagram of Xiao Liang when he looks at distant objects. He has _ _ _ _ _ _ _ eyes. The correction method is to wear glasses made of _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Answer: myopia; weaken

(Changchun, 2006) The human eyeball is like a camera, and the interaction between the lens and the cornea is equivalent to a _ _ _ _ _ _ _ _ lens. The light emitted by the object will form an image of _ _ _ _ _ _ _ _ _ _ _ _ _ on the retina (choose "upright" or "upright". If you don't pay attention to eye hygiene for a long time, it will lead to myopia. There is an operation to treat myopia, which is to treat the cornea with laser, so that the lens composed of lens and cornea becomes _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ (fill in "strong" or "weak").

Answer: Convex (or convergent); Fall head; faint

(jinzhou area, 2006) Xiao Qiang shot with a camera with a certain focal length. If he keeps the camera away from the scene being shot, the clear image of the scene on the negative will be _ _ (choose "bigger", "smaller" or "unchanged").

Answer: smaller

(Yunnan, 2006) Convex lenses can focus light. The focal length of the camera lens is 15cm. To get a clear portrait on the negative, the distance between the person and the camera should be 30cm (fill in "greater than", "less than" or "equal to"). The image formed on the negative is an image (fill in "real" or "virtual").

Answer: greater than; solid

(Zhaoxing, 2006) The human eye is very similar to a camera in structure. The lens is equivalent to a convex lens, which can image objects on the retina. In the following diagrams A and B, for myopia, glasses and lenses (optional: "C" or "D") should be selected for correction.

Answer: a, d

Third, painting questions:

(Guangzhou, 2006) Draw the trajectory of ray AB passing through the convex lens in figure 13.

(Chaoyang District, Beijing, 2006) As shown in Figure 9, according to the refraction of light, fill the dotted box with appropriate lenses.

(Leshan, Sichuan, 2006) Complete lens light path diagram 1.

(Xiamen, 2006) In figure 12, the light beam refracts from the left to the convex lens and then to the concave lens.

(Hebei, 2006) was drawn according to the following requirements. Fig. a is a schematic diagram of distant objects imaging in someone's eyes. Please fill in the dotted box in Figure B with appropriate lenses to make distant objects image on the retina.

(Taizhou, 2006) Please draw the approximate position of the nearsighted object in figure 10, and mark the image point A' corresponding to point A on the object.

(jinzhou area, 2006) Please draw the refracted light of incident light in Figure 4.

answer

(Taian, 2006) According to the incident light or refracted light in the following two pictures, the corresponding refracted light or incident light is made respectively.

Fourth, the experimental questions:

Lianyungang (2006) used a lens with a focal length of 10cm in the convex lens imaging experiment. A classmate can't get a complete candle flame image by moving the screen left and right after placing the candle and lens as shown in the picture below. The reason is. After proper adjustment (the object distance remains the same), students move the light screen until the candle flame on the light screen is clear and complete. The essence of images is.

Answer: The centers of candle flame, lens and light screen are not at the same height; Inverted and enlarged real image

(Wuxi, 2006) Xiaoming stood in the same position and took two photos of Xishan, a famous scenic spot in Wuxi, with a digital camera (the focal length can be changed), as shown in the figure. He raised the question: What is the relationship between the size of the object imaged on the screen by a convex lens and the focal length of the lens? Xiao Ming explored this.

(1) Xiaoming found some convex lenses, but he didn't know their focal lengths. Please provide him with a method to measure the focal length of the lens. (Examples can be given)

(2) After measuring the focal lengths of convex lenses, Xiao Ming chose three convex lenses with focal lengths of 15cm, 10cm and 5cm, and conducted experiments in turn while keeping the object distance at 35cm, and found that the images obtained were getting smaller and smaller. Please judge which photo Xiao Ming took according to the experimental results. The camera lens has a large focal length.

(3) In the process of inquiry, Xiao Ming always keeps the distance between objects unchanged. Please tell me the reason why he did it.

Answer: (1) Point the convex lens at the sun, put a piece of paper on the other side of the lens, and adjust the distance between the lens and the paper until the smallest and brightest light spot appears on the paper. Measuring the distance between the spot and the convex lens is the focal length of the convex lens (other methods are also given correctly).

(2) The focal length of the camera lens is larger when the second photo is taken.

(3) The size of the real image formed by the convex lens is related to the object distance and focal length, so when studying the relationship between the size and focal length of the real image, the object distance should remain unchanged.

(Fuzhou, 2006) Please read the following carefully and answer the questions as required.

The human eye

The human eye is much like a camera. The difference between eyes and cameras is that people's eyes change the focal length of the lens by adjusting the bending degree of the lens, and get a clear and restored real image, as shown in figure 17; Ordinary cameras make images clear by changing the image distance when the object distance is determined. The farthest point that the eyes can see clearly is called the far point, and the far point of normal eyes is extremely far. The closest point that the eyes can see clearly is called the near point, and the near point of normal eyes is about 10cm away from the eyes. Eyes are important organs of human body. Long-term use of eyes, such as reading, watching TV and computer, will cause eye fatigue. The common symptoms of eye fatigue are headache, brain swelling and dry eyes. The distance to gaze at an object for a long time without fatigue is called apparent distance, and the apparent distance of normal eyes is 25cm.

(1) Please complete the properties of the image in the text.

(2) People's eyes get a clear image by changing the lens, while ordinary cameras make the image clear by changing the object distance.

(3) According to the above, what do you think is the observation range of normal eyes? (Fill in the following options).

A.0 ~ 10 cm b. 10 cm ~ 25 cm c. 10 cm, an extreme distance of D.0 ~ 25 cm.

(4) How to prevent eye fatigue, please make reasonable suggestions.

Answer: (1) handstand; (2) focal length (or curvature) and image distance; (3)c； (4) Let the distance between the object and the eyes be 25 cm (or don't read for a long time, take a proper rest in the middle, or do more eye exercises) (other suggestions are reasonable).

(Fuzhou, 2006) As shown in figure 12, Zhou Qian and several students got a clear real miniature inverted image on the optical screen when they were doing the experiment of "Exploring the imaging law of convex lens". At this time, Zhou Qian put the lens of his myopia glasses between the candle and the convex lens (close to the lens), and the original clear image on the screen became blurred.

(1) In order to make the image on the screen clear again, how to move the screen without moving the candle and lens?

_________________________________________________________________

(2) In the four small pictures shown in Figure 13, it is () that correctly represents the imaging situation and correction practice of myopia in Zhou Qian.

a、②① B、①③ C、②④ D、③④

Answer: (1) The screen is far away from the convex lens; (2)B

(Shaoguan, 2006) Xiaoming used optical bench, convex lens (focal length: 10cm), candle, match and light screen to do the experiment of "exploring the imaging law of convex lens".

(1) There are three sliders A, B and C on the optical bench, which are used to place convex lenses, light screens or candles (as shown in the left figure below), among which B should be placed:

(2) It is found in the experiment that the image on the light screen is as shown on the right. What do you think is the reason for this phenomenon:

(3) When observing and recording convex lens imaging, measure and.

(4) Place the candle at a distance of 0/6 cm from the convex lens/kloc-and move the screen back and forth. Xiao Ming (fill in "can" or "can't") can see a clear image on the screen.

(5) Then Xiao Ming covers the upper part of the convex lens with opaque cardboard, and then moves the screen back and forth. male

(Fill in "can" or "can't") See the complete image on the screen.

Answer: (1) Convex lens (2) The centers of candle, convex lens and light screen are not on the same horizontal line.

(3) object distance; The image distance (4) can (5) can

(Nantong, 2006) In the experiment of studying the imaging law of convex lens with optical bench;

(1) Measure the focal length of the convex lens as shown in the figure, and the focal length of the convex lens is _ _ _ _ _ cm.

(2) Place the candle, convex lens and light screen on the optical bench in turn. After lighting the candle, adjust the center of the candle flame, convex lens and light screen to about _ _ _ _ _ _ _ _ _ _ _.

(3) When the candle flame is 30cm away from the convex lens, a clear inverted reality can be obtained by moving the light curtain.

Image. _ _ _ _ _ _ works by using this imaging law (filling optical instruments).

Answer: (1) 9.4 (9.2-9.5) (2) Same height (3) Reduced; camera

Inner Mongolia (2006) gives you a shot. I don't know whether it is a convex lens or a concave lens. Please briefly describe three ways to judge.

A: (1)

(2)

(3)

Answer: (1) The lens faces the sunlight (parallel light source), and the bright spot on the other side indicates a convex lens.

(2) Touch by hand. Thick in the middle and thin on both sides are convex lenses.

(3) Light the candle and see if it can be imaged on another screen. What can be imaged is a convex lens.