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11TH GRADE PRACTICE

Physics Problems: Optics, Grade 11

Reflection, refraction, lenses and diffraction.

12 problems2 subtopics
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CONDITIONS

Problems

12
№ 37

Problem 37

Geometric optics

The angle of incidence of the beam is 40∘40^{\circ}, the refractive index of the medium is 1,51{,}5. What is the angle of refraction?

  1. 50,8 ∘50{,}8\,^{\circ}
  2. 254 ∘254\,^{\circ}
  3. 25,4 ∘25{,}4\,^{\circ}
  4. 12,7 ∘12{,}7\,^{\circ}
№ 38

Problem 38

Lenses, interference and diffraction

The distance from the object to an image of equal size is 80 cm80\,\text{cm}. Determine the focal length and optical power of the lens.

  1. (0,1 m; 2,5 dpfr)\left(0{,}1\,\text{m};\ 2{,}5\,\text{dpfr}\right)
  2. (0,4 m; 10 dpfr)\left(0{,}4\,\text{m};\ 10\,\text{dpfr}\right)
  3. (2 m; 50 dpfr)\left(2\,\text{m};\ 50\,\text{dpfr}\right)
  4. (0,2 m; 5 dpfr)\left(0{,}2\,\text{m};\ 5\,\text{dpfr}\right)
№ 41

Problem 41

Geometric optics

The height of the Sun above the horizon is 20∘20^{\circ}. At what angle to the horizon should a mirror be placed to illuminate the bottom of a vertical well?

  1. 110 ∘110\,^{\circ}
  2. 550 ∘550\,^{\circ}
  3. 55 ∘55\,^{\circ}
  4. 27,5 ∘27{,}5\,^{\circ}
№ 42

Problem 42

Geometric optics

At an angle of incidence of 40∘40^{\circ}, the angle of refraction is 24∘24^{\circ}. Determine the refractive index, the speed of light in the substance, and the limiting angle of total internal reflection. What will happen at an angle of incidence of 40∘40^{\circ} from the substance into the air?

  1. (n=1,5; 2⋅108 m/s; 41,8∘; prelomlenie)\left(n=1{,}5;\ 2\cdot10^8\,\text{m/s};\ 41{,}8^{\circ};\ \text{prelomlenie}\right)
  2. (n=0,63; 4,8⋅108 m/s; 50∘; ofrazheniya net)\left(n=0{,}63;\ 4{,}8\cdot10^8\,\text{m/s};\ 50^{\circ};\ \text{ofrazheniya net}\right)
  3. (n=1,58; 3⋅108 m/s; 90∘; prelomlenie)\left(n=1{,}58;\ 3\cdot10^8\,\text{m/s};\ 90^{\circ};\ \text{prelomlenie}\right)
  4. (n=1,58; 1,9⋅108 m/s; 39,3∘; usefulnoe ofrazhenie)\left(n=1{,}58;\ 1{,}9\cdot10^8\,\text{m/s};\ 39{,}3^{\circ};\ \text{usefulnoe ofrazhenie}\right)
№ 43

Problem 43

Geometric optics

What must be the refractive index of a substance so that the reflected and refracted rays make an angle of 90∘90^{\circ}? Express your answer in terms of the angle of incidence α\alpha.

  1. n=tan⁡α, n bezrazmerenn=\tan\alpha,\ n\text{ bezrazmeren}
  2. n=sin⁡α, n bezrazmerenn=\sin\alpha,\ n\text{ bezrazmeren}
  3. n=cos⁡α, n bezrazmerenn=\cos\alpha,\ n\text{ bezrazmeren}
  4. n=cot⁡α, n bezrazmerenn=\cot\alpha,\ n\text{ bezrazmeren}
№ 44

Problem 44

Lenses, interference and diffraction

The object is located at a distance of 20 cm20\,\text{cm} from the lens, the image is 33 times larger than the object. Determine the possible focal lengths and optical powers for real and virtual images.

  1. (150 sm; 66,7 dpfr; 300 sm; 33,3 dpfr)\left(150\,\text{sm};\ 66{,}7\,\text{dpfr};\ 300\,\text{sm};\ 33{,}3\,\text{dpfr}\right)
  2. (15 sm; 6,67 dpfr; 30 sm; 3,33 dpfr)\left(15\,\text{sm};\ 6{,}67\,\text{dpfr};\ 30\,\text{sm};\ 3{,}33\,\text{dpfr}\right)
  3. (7,5 sm; 3,335 dpfr; 15 sm; 1,665 dpfr)\left(7{,}5\,\text{sm};\ 3{,}335\,\text{dpfr};\ 15\,\text{sm};\ 1{,}665\,\text{dpfr}\right)
  4. (30 sm; 13,34 dpfr; 60 sm; 6,66 dpfr)\left(30\,\text{sm};\ 13{,}34\,\text{dpfr};\ 60\,\text{sm};\ 6{,}66\,\text{dpfr}\right)
№ 45

Problem 45

Lenses, interference and diffraction

A lens with a focal length of 20 cm20\,\text{cm} gives a magnification of 55 times. Determine the distance between the object and the image. What values ​​are possible if the image is reduced by 55 times?

  1. (288 sm; 128 sm; 288 sm)\left(288\,\text{sm};\ 128\,\text{sm};\ 288\,\text{sm}\right)
  2. (1440 sm; 640 sm; 1440 sm)\left(1440\,\text{sm};\ 640\,\text{sm};\ 1440\,\text{sm}\right)
  3. (144 sm; 64 sm; 144 sm)\left(144\,\text{sm};\ 64\,\text{sm};\ 144\,\text{sm}\right)
  4. (72 sm; 32 sm; 72 sm)\left(72\,\text{sm};\ 32\,\text{sm};\ 72\,\text{sm}\right)
№ 46

Problem 46

Lenses, interference and diffraction

Coherent waves with a frequency of 5⋅1014 Hz5\cdot10^{14}\,\text{Hz} interfere in the air. Will the light increase or decrease at a point with a path difference of 2,4 μm2{,}4\,\text{μm}?

  1. Δr=7λ2, oslablenie\Delta r=7\dfrac{\lambda}{2},\ \text{oslablenie}
  2. Δr=4λ, oslablenie\Delta r=4\lambda,\ \text{oslablenie}
  3. Δr=3λ2, usilenie\Delta r=3\dfrac{\lambda}{2},\ \text{usilenie}
  4. Δr=8λ2, usilenie\Delta r=8\dfrac{\lambda}{2},\ \text{usilenie}
№ 47

Problem 47

Lenses, interference and diffraction

Monochromatic light is normally incident on a diffraction grating with a period of 1/200 mm1/200\,\text{mm}. The third-order maximum is visible at an angle of 17,5∘17{,}5^{\circ}. Determine the wavelength and the speed and wavelength in glass with n=1,5n=1{,}5. How will the frequency and wavelength change when the frequency is doubled?

  1. (5⋅10−7 m; 3,33⋅10−7 m; 2⋅108 m/s; 6⋅1014 Gts; 2,5⋅10−7 m; 1,67⋅10−7 m)\left(5 \cdot 10^{-7}\,\text{m};\ 3{,}33 \cdot 10^{-7}\,\text{m};\ 2 \cdot 10^{8}\,\text{m/s};\ 6 \cdot 10^{14}\,\text{Gts};\ 2{,}5 \cdot 10^{-7}\,\text{m};\ 1{,}67 \cdot 10^{-7}\,\text{m}\right)
  2. (2,5⋅10−7 m; 1,665⋅10−7 m; 1⋅108 m/s; 3⋅1014 Gts; 1,25⋅10−7 m; 8,35⋅10−8 m)\left(2{,}5 \cdot 10^{-7}\,\text{m};\ 1{,}665 \cdot 10^{-7}\,\text{m};\ 1 \cdot 10^{8}\,\text{m/s};\ 3 \cdot 10^{14}\,\text{Gts};\ 1{,}25 \cdot 10^{-7}\,\text{m};\ 8{,}35 \cdot 10^{-8}\,\text{m}\right)
  3. (1⋅10−6 m; 6,66⋅10−7 m; 4⋅108 m/s; 1,2⋅1015 Gts; 5⋅10−7 m; 3,34⋅10−7 m)\left(1 \cdot 10^{-6}\,\text{m};\ 6{,}66 \cdot 10^{-7}\,\text{m};\ 4 \cdot 10^{8}\,\text{m/s};\ 1{,}2 \cdot 10^{15}\,\text{Gts};\ 5 \cdot 10^{-7}\,\text{m};\ 3{,}34 \cdot 10^{-7}\,\text{m}\right)
  4. (5⋅10−6 m; 3,33⋅10−6 m; 2⋅109 m/s; 6⋅1015 Gts; 2,5⋅10−6 m; 1,67⋅10−6 m)\left(5 \cdot 10^{-6}\,\text{m};\ 3{,}33 \cdot 10^{-6}\,\text{m};\ 2 \cdot 10^{9}\,\text{m/s};\ 6 \cdot 10^{15}\,\text{Gts};\ 2{,}5 \cdot 10^{-6}\,\text{m};\ 1{,}67 \cdot 10^{-6}\,\text{m}\right)
№ 48

Problem 48

Lenses, interference and diffraction

The diffraction grating has 8585 slits per 1 mm1\,\text{mm}. What is the angle between the second-order purple maxima at λ=4⋅10−7 m\lambda=4\cdot10^{-7}\,\text{m}?

  1. 78 ∘78\,^{\circ}
  2. 7,8 ∘7{,}8\,^{\circ}
  3. 3,9 ∘3{,}9\,^{\circ}
  4. 15,6 ∘15{,}6\,^{\circ}
№ 49

Problem 49

Lenses, interference and diffraction

The focal length of the projection lamp lens is 15 cm15\,\text{cm}. The slide is located at a distance of 15,6 cm15{,}6\,\text{cm} from the lens. What linear magnification does the flashlight provide?

  1. 50 raz50\,\text{raz}
  2. 250 raz250\,\text{raz}
  3. 25 raz25\,\text{raz}
  4. 12,5 raz12{,}5\,\text{raz}
№ 52

Problem 52

Lenses, interference and diffraction

At a distance of 1,5 m1{,}5\,\text{m} from the screen there is a diffraction grating with a period of 20 μm20\,\text{μm}. At what distance from the central maximum is the second-order violet maximum at λ=4⋅10−7 m\lambda=4\cdot10^{-7}\,\text{m}?

  1. 0,6 m0{,}6\,\text{m}
  2. 0,06 m0{,}06\,\text{m}
  3. 0,03 m0{,}03\,\text{m}
  4. 0,12 m0{,}12\,\text{m}

THEORY

Lessons on the topic

Reflection and refraction of lightLaws of reflection, refraction and total internal reflection.Lenses and diffractionLens formula, magnification, optical power and diffraction grating.

DIRECTORY

Formulas by topic

Lens powerD · diopterPeriodT · withRefractive indexn · dimensionlessDistance and pathS, l · mLens magnificationΓ · dimensionlessFocal lengthF · m