1. The fisherman meets the sunrise on the lake in calm weather. Choose the correct statement.
A. The image of a fisherman in the mirror surface of the lake is reduced.
B. Beams of light coming from the Sun change their direction on the surface of the water.
B. The angle of refraction of the sun's rays is measured from the horizontal surface of the water.
D. The speed of light in air is equal to the speed of light in water.
2. The figure shows a glass lens in the air. An object AB is in front of the lens. Choose the correct statement.
A. The image of the object AB in the lens is real.
B. The image of the object AB in the lens is imaginary.
B. The image of the object AB in the lens is enlarged.
D. The image of the object AB is between the lens and its main focus.
3. The optical power of the lenses of glasses, respectively, is 1.25 diopters; 2 diopters; 4 diopters What are the focal lengths of these lenses?
4. How and why do the outlines of the shadow and penumbra of a person change when he moves away from a street lamp in the evening?
The blurring of the outline of the shadow when moving away from the street lamp occurs due to the diffraction (enveloping of obstacles) of light and an increase in the distance between a person and his shadow (on the ground). The angle of incidence of rays from the source to the object changes.
5. The lamp is at a very large distance from the converging lens. It is brought closer to the lens until it comes into contact with it. Where will the image of the lamp move? How will the appearance of the image change?
download Test work No. 4
"Phenomena of Light"
Level 1
OptionI
The angle of incidence of the beam is 25 0 . What is the angle between the incident and reflected rays?
3. Which glasses are designed for a near-sighted person, and which ones are for a far-sighted person, if the optical powers of their lenses are as follows: +1 diopter, +2 diopter, -1.5 diopter, -2.5 diopter?
OptionII
The angle between the incident and reflected rays is 60°. At what angle does the light hit the mirror?
The optical power of the lens is -2.5 diopters. Calculate its focal length. What kind of lens is it - diverging or converging?
What kind of lenses (converging or diverging) are in glasses designed for nearsighted people? Justify your answer.
Level 2
OptionI
What is the difference between a real image and a virtual one?
When the optical power of the eye is greater; when looking at distant or near objects?
OptionII
1. The distance from an object to its image in a flat mirror is 80 cm. What is the distance from the object to the mirror? 
3. Redrawing fig. in a notebook, show on it the areas of shadow and penumbra formed behind an opaque object BC, which is illuminated by two light sources A 1 and A 2.
Level 3
OptionI
On a sunny day, the length of the shadow on the ground from a person 1.8 m tall is 90 cm, and from a tree - 10 m. What is the height of the tree? (Answer: 20 m)
OptionII
(Answer: real, inverted, enlarged)
Level 4
OptionI
OptionII
OPTION 3|
1. Why, while in a boat, is it difficult to hit with a spear (sharp) a fish swimming nearby?
2. Why is it impossible to water the flowers in the garden on a sunny summer day?
3. Redrawing the drawing in a notebook, show on it the areas of shadow and penumbra formed behind an opaque object sun, which is illuminated by two light sources A 1 and A 2 .
OPTION 4
1. Under what condition can a converging lens give an image of an object equal in size to the object itself?
2. When is the optical power of the eye greater: when considering distant or close objects?
3.Build the image of the subject CD in a flat mirror AB. Find the area in which the eye will see the image of the entire object.
C
OPTION 5B
1. A beam of light falls on a flat interface between two media. The angle of incidence is 40°, the angle between the reflected beam and the refracted beam is 110°. What is the angle of refraction?
3. Between the luminous dot A and a plane-parallel plate was placed with the eye. Create an image of point A.
OPTION 6
1. With what speed does the object move away from the mirror if the image of the object moves away from the object at a speed of 80 cm/s?
2. A fly has landed on the lens of the camera lens. How will this affect the quality of the picture?
3. The figure shows the course of parallel rays reflected from the surface. Which of these surfaces are mirror-like, which ones have roughness? Why? Explain.
Enough level
OPTION 1
1. Why in a room illuminated by one lamp, rather sharp shadows from objects are obtained, and in a room where a chandelier serves as a source of illumination, such shadows are not observed?
2. The figure shows the position of the optical axis MM thin lens, luminous point A and its image A 1 . Find by construction the position of the center of the lens and its foci. What is this lens?
3. The object is at a distance of 40 cm from the converging lens. What will be the image of the object (real or imaginary, direct or inverted, enlarged or reduced), if the optical power of the lens is 4 diopters?
4. The lens of the projection apparatus has a focal length of 15 cm. At what distance should a 9*12 cm slide be placed from the lens in order to get an image of 45*60 cm on the screen?
OPTION 2
1. The shadow of the football goal post in the morning and evening is longer than during the day. Does the length of the shadow from the crossbar change during the day?
2. Given points A and A 1 on the axis of a lens of unknown shape. Determine the type of lens (converging or diverging). Plot the foci of the lens.
3. On a sunny day, the length of the shadow on the ground from a person 1.8 m tall is 90 cm, and from a tree - 10 m. What is the height of the tree?
4. What is the main focal length of a converging lens if the image of an object located at a distance of 20 cm from the lens is magnified 4 times?
OPTION 3
1. In indoor stadiums, you can often see that the athletes on the field have four shadows. How can this be explained?
2. The figure shows the path of the beam after refraction in a diverging lens. Find by construction the path of this ray to the lens.
3. The lens gives a virtual image of an object located at a distance of 35 cm from the lens. Can the optical power of a lens be 2.5 diopters? Consider the cases of converging and diverging lenses.
4. The lens gives a threefold increase in an object located at a distance of 10 cm from it. Find the focal length of the lens.
OPTION 4
1. How do the dimensions of the light source affect the width of the penumbra?
2. A layered lens is made from two types of glass with different refractive indices. What image of a point light source will this lens give? Consider that the light is completely absorbed at the boundaries between the layers.
3. On a sunny day, the length of the shadow on the ground from the house is 40 m, and from a tree 3 m high, the length of the shadow is 4 m. What is the height of the house?
4. From what distance was the photo of the train taken if the height of the car in the picture is 9 mm, and the actual height of the car is 3 m? The focal length of the camera lens is 15 cm.
OPTION 5
1. By what sign can you find that you are in the penumbra of some object?
2. The figure shows the position of the object AB and his images A 1 B 1 . Find by construction the position of the lens and the location of its foci.
IN 1
3. Where can an object be located if a converging lens with a focal length of 20 cm gives its actual image? What will this image be - straight or inverted?
4. The camera lens has a focal length of 10.5 cm. At what distance from the lens should an object be placed in order for the picture to be 5 times smaller than the size of the object?
OPTION 6
1. How and why do the outlines of the shadow and penumbra of a person change when he moves away from a street lamp in the evening?
2. Draw an image of a slanted arrow AB, passing through the focus of the converging lens.
3. The street lamp hangs at a height of 3m. A stick 1.2 m long, placed vertically in a certain place, casts a shadow, the length of which is equal to the length of the stick. How far from the base of the post is the stick?
4. The distance between the object and the screen is 120cm. Where should a converging lens with a focal length of 25 cm be placed in order to get a clear image of the object on the screen?
High level
OPTION 1
1. Air bubbles located on the stems and leaves of underwater plants seem to be silver-mirror. Why?
2. A converging lens with a focal length of 20 cm is at a distance of 10 cm from a diverging lens with a focal length of 60 cm. Find at what distance from the second lens the image of point A will be obtained if the luminous point itself is at a distance of 30 cm from the first lens.
3. Build the path of the rays and determine the position of the image of the object AB in an optical system consisting of a converging lens and a flat mirror.
4. A person standing on the shore of a reservoir sees in the smooth surface of the water an image of the sun, whose height above the horizon is 25 °. Sitting down on a bench, he drew attention to the fact that the image of the sun in the water approached him by 240 cm. Find the height of the bench if the person's height is 160 cm.
OPTION 2
1. How is the rainbow located relative to the Sun? Why is it shaped like an arc?
2. A converging lens gives a three times enlarged real image of the object. To get a three times enlarged, but virtual image, the lens was moved to the side of the object by 10 cm. What is the focal length and optical power of the lens?
3. How should three converging lenses be positioned so that parallel rays, passing through the lenses, remain parallel?
4. Construct the further course of the beam in the prism. n 2-1 =3.
OPTION 3
1. Is it possible to say that the image of an object in the mirror is absolutely identical to it (the same with it)?
2. Two converging lenses with focal lengths of 2 cm and 20 cm are placed at a distance of 24 cm from each other. Construct an image of an object at a distance of 3 cm from the first lens. Find the increase G.
3. AB- item, A 1
B 1
-
item image, 
The optical power of the lens is 40 diopters. Find the distance from the object to the lens and from the image to the lens. Check the calculation by construction.
4. Two flat mirrors are placed at an angle to each other. A point source of light was placed between them, and as a result we got P= 11 images of this source in mirrors. What is the angle α between the mirrors?
VARIANT 4
1. What vision defect will “appear” in a fish that is taken out of the water - myopia or hyperopia?
2. Two converging lenses with focal lengths of 10 cm and 15 cm produce an image of an object 2 cm high located at a distance of 10 cm from the first lens. Find the height of the image of the object given by the lens system. Create an image of an object.
3.The figure shows the position of the optical axis MM thin lens and beam path ABC. Find by construction the path of an arbitrary ray KE.
4. Find number of images P point source of light obtained in two flat mirrors forming an angle of 60° with each other. The origin is on the bisector of the angle.
OPTION 5
1. The edges of the lens were cut off. Has its focal length changed?
2. With what shutter speed should a runner be photographed, whose speed is 3 m / s, so that the image blur does not exceed 0.1 mm? The focal length of the lens is 15 cm, the distance from the camera to the runner is 10 m.
3. Construct the further course of the beam in the prism, if the angle of incidence is 70°, and the refractive index is 1.6.
4. Two flat rectangular mirrors form a dihedral angle of 178°. A point source of light is located at a distance of 8 cm from the line of contact of the mirrors and at the same distance from each of them. Determine the distance between the imaginary images of the source in the mirrors.
OPTION 6
1. Road bumps are less visible during the day than at night when the road is illuminated by car headlights. Why?
2. A beam of parallel rays passes through two thin lenses while remaining parallel. The distance between the lenses is 15 cm. Determine the focal length of the first lens if it is 9 cm for the second lens.
3. Construct a further path of the beam, if the angle of incidence is 40, the refractive index is 2.
4. A light beam is incident on one of two flat mirrors that form an acute dihedral angle of 30° in a plane perpendicular to the mirrors. After being reflected from the mirrors 5 times, the beam goes back in the same direction. Determine the angle of incidence of the beam.
Test № 3
WAVE OPTICS
First level
OPTION 1
1. What is the phenomenon of light dispersion? Which device is based on this phenomenon?
2. What condition is necessary for observing a diffraction pattern? List all correct answers.
A. The size of the obstacle is much larger than the wavelength.
B. The dimensions of the obstacle are comparable to the wavelength.
B. The dimensions of the obstacle are much greater than the amplitude of the wave.
3. Among the following, indicate the pair of phenomena in which the wave properties of light are most clearly manifested. List all correct statements.
A. Reflection and dispersion.
B. Refraction and polarization.
B. Diffraction and interference.
OPTION 2
1. Name the characteristic features of the phenomenon of light diffraction. Under what conditions is this phenomenon clearly observed?
2. Which color of light is deflected the least by the prism of a spectroscope? List all correct answers.
A. Violet.
B. Green.
B. Red.
3. What phenomenon is associated with the difference in the speed of propagation of the speed of light in matter? List all correct answers.
A. Dispersion.
B. Interference.
B. Diffraction.
OPTION 3
1. Name the characteristic features of the phenomenon of light interference. Under what conditions is this phenomenon clearly observed?
2. How will the frequency of red radiation change when light passes from air to water? List all correct answers.
A. Increases.
B. Decreases.
B. Does not change.
3. What is the nature of light waves? List all correct answers.
A. Transverse, like sound waves in solids.
B. Longitudinal, like sound waves in gases.
B. They can be both longitudinal and transverse, like mechanical waves in elastic media.
OPTION 4
1. What does dispersion mean?
2. Which of the following phenomena is due to the interference of light? List all correct answers.
A. Iridescent coloration of thin oil films.
B. Newton's rings.
B. Deviation of light rays in the area of geometric shadow.
3. Which of the following expressions are the condition for observing the main maxima in the spectrum of a diffraction grating with a periodd at an angle φ? List all correct answers.
A. 
IN. 
OPTION 5
1. Explain how and why wave diffraction occurs?
2. Light passes from air to glass with a refractive index of 1.5. Which of the following statements is true? List all correct answers.
A. The frequency and speed of light decreased by 1.5 times.
B. The frequency and speed of light increased 1.5 times.
B. The frequency has not changed, but the speed of light has decreased by 1.5 times
3. What phenomenon proves the transverseness of light waves?
A. Dispersion.
B. Reflection.
B. Polarization.
OPTION 6
1. What is the phenomenon of light interference? Give examples.
2. How will the length of the yellow radiation change when passing from air to water? List all correct answers.
A. Decreases.
B. Increases.
B. Does not change.
3. What is easier to observe in everyday life: the diffraction of sound or light waves? List all correct answers.
A. Diffraction of sound waves, since they are longitudinal, and light waves are transverse.
B. Diffraction of sound waves, since .
B. Diffraction of light waves, since 
Average level
OPTION 1
1. If you look at the light of a street lamp through your eyelashes, a rainbow light appears around it. How can this be explained?
2. How many times will the wavelength of light change when passing from air to glass, if the speed of light in glass is 2 10 8 m/s?
3. The diffraction grating has 50 lines per millimeter. At what angle is the second-order maximum of monochromatic radiation with a wavelength of 400 nm visible?
OPTION 2
1. Does the speed of propagation of light radiation depend on the frequency of oscillations? from the wavelength?
2. How many wavelengths of monochromatic radiation with a frequency
6 10 14 Hz fit on a segment of 1m?
3. Determine the optical path difference of waves 540 nm long that have passed through the diffraction grating and formed a second-order maximum.
OPTION 3
1. Why does the color of the wings of an insect change when viewed from different angles?
2. The wavelength of yellow light in air is 580 nm, and in liquid 400 nm. Determine the refractive index of the liquid.
3. Determine the length of the light wave if a second-order maximum occurs in the diffraction spectrum at an optical difference in the wave path of 1.15 μm.
OPTION 4
1. What light waves are called coherent.
2. Light waves in some liquid have a wavelength of 500 nm and a frequency of 4.5 10 14 Hz. Determine the absolute refractive index of this liquid.
3. Monochromatic radiation with a wavelength of 750 nm is passed through a diffraction grating having 200 lines per millimeter. Determine the angle at which the maximum of the first order of this wave is visible.
OPTION 5
1. Why don't conventional light sources emit coherent waves?
2. What vibration frequencies correspond to the red rays of the visible part of the spectrum with a wavelength of 700 nm?
3. The diffraction grating has 50 lines per millimeter. At what angle is the first-order maximum of monochromatic radiation with a wavelength of 400 nm visible?
OPTION 6
1. What properties of light are confirmed by the phenomenon of interference?
2. What vibration frequencies correspond to the violet rays of the visible part of the spectrum with a wavelength of 400 nm?
3. Find the highest order of the spectrum for the yellow sodium line with a wavelength of 5.89 10 -7 m, if the period of the diffraction grating is 2 μm.
Enough level
Test work No. 4"Phenomena of Light"
Level 1
OptionI
The angle of incidence of the beam is 25 0 . What is the angle between the incident and reflected rays?
3. Which glasses are designed for a near-sighted person, and which ones are for a far-sighted person, if the optical powers of their lenses are as follows: +1 diopter, +2 diopter, -1.5 diopter, -2.5 diopter?
OptionII
The angle between the incident and reflected rays is 60°. At what angle does the light hit the mirror?
The optical power of the lens is -2.5 diopters. Calculate its focal length. What kind of lens is it - diverging or converging?
What kind of lenses (converging or diverging) are in glasses designed for nearsighted people? Justify your answer.
Level 2
OptionI
What is the difference between a real image and a virtual one?
When the optical power of the eye is greater; when looking at distant or near objects?
OptionII
1. The distance from an object to its image in a flat mirror is 80 cm. What is the distance from the object to the mirror? 
3. Redrawing fig. in a notebook, show on it the areas of shadow and penumbra formed behind an opaque object BC, which is illuminated by two light sources A 1 and A 2.
Level 3
OptionI
