InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The resolving power of a telescope can be increased by: A. increasing the objective focal length and decreasing the eyepiece focal length B. increasing the lens diameters C. decreasing the lens diameters D. inserting a correction lens between objective and eyepiece E. none of the above |
|
Answer» B. increasing the lens diameters |
|
| 2. |
One of the two slits in a Young’s experiment is painted over so that it transmits only one-half the intensity of the other slit. As a result: A. the fringe system disappears B. the bright fringes get brighter and the dark ones get darker C. the fringes just get dimmer D. the dark fringes just get brighter E. the dark fringes get brighter and the bright ones get darker |
|
Answer» E. the dark fringes get brighter and the bright ones get darker |
|
| 3. |
A liquid of refractive index n = 4/3 replaces the air between a fixed wedge formed from two glass plates as shown. As a result, the spacing between adjacent dark bands in the interference pattern:A. increases by a factor of 4/3 B. increases by a factor of 3 C. remains the same D. decreases to 3/4 of its original value E. decreases to 1/3 of its original value |
|
Answer» D. decreases to 3/4 of its original value |
|
| 4. |
If white light is incident on a diffraction grating: A. the first order lines for all visible wavelengths occur at smaller diffraction angles than any of the second order lines B. some first order lines overlap the second order lines if the ruling separation is small but do not if it is large C. some first order lines overlap second order lines if the ruling separation is large but do not if it is small D. some first order lines overlap second order lines no matter what the ruling separation E. first and second order lines have the same range of diffraction angles |
|
Answer» A. the first order lines for all visible wavelengths occur at smaller diffraction angles than any of the second order lines |
|
| 5. |
Two nearly equal wavelengths of light are incident on an N-slit grating. The two wavelengths are not resolvable. When N is increased they become resolvable. This is because: A. more light gets through the grating B. the lines get more intense C. the entire pattern spreads out D. there are more orders present E. the lines become more narrow |
|
Answer» E. the lines become more narrow |
|
| 6. |
Monochromatic light is normally incident on a diffraction grating. The mth order line is at a diffraction angle θ and has width w. A wide single slit is now placed in front of the grating and its width is then slowly reduced. As a result: A. both θ and w increase B. both θ and w decrease C. θ remains the same and w increases D. θ remains the same and w decreases E. θ decreases and w increases |
|
Answer» C. θ remains the same and w increases |
|
| 7. |
A mixture of 450-nm and 900-nm light is incident on a diffraction grating. Which of the following is true? A. all lines of the 900-nm light coincide with even order lines of the 450-nm light B. all lines of the 450-nm light coincide with even order lines of the 900-nm light C. all lines of the 900-nm light coincide with odd order lines of the 450-nm light D. None of the lines of the 450-nm light coincide with lines of the 900-nm light E. All of the lines of the 450-nm light coincide with lines of the 900-nm light |
|
Answer» A. all lines of the 900-nm light coincide with even order lines of the 450-nm light |
|
| 8. |
A light beam incident on a diffraction grating consists of waves with two different wavelengths. The separation of the two first order lines is great if: A. the dispersion is great B. the resolution is great C. the dispersion is small D. the resolution is small E. none of the above (line separation does not depend on either dispersion or resolution) |
|
Answer» A. the dispersion is great |
|
| 9. |
Which of the following is true for Bragg diffraction but not for diffraction from a grating? A. Two different wavelengths may be used B. For a given wavelength, a maximum may exist in several directions C. Long waves are deviated more than short ones D. There is only one grating spacing E. Maximum occur only for particular angles of incidence |
|
Answer» E. Maximum occur only for particular angles of incidence |
|
| 10. |
As more slits with the same spacing are added to a diffraction grating the lines: A. spread farther apart B. move closer together C. become wider D. becomes narrower E. do not change in position or width |
|
Answer» D. becomes narrower |
|
| 11. |
Consider a single-slit diffraction pattern caused by a slit of width a. There is a maximum if sin θ is equal to: A. slightly more than 3λ/2a B. slightly less than 3λ/2a C. exactly 3λ/2a D. exactly λ/2a E. very nearly λ/2a |
|
Answer» B. slightly less than 3λ/2a |
|
| 12. |
If two light waves are coherent: A. their amplitudes are the same B. their frequencies are the same C. their wavelengths are the same D. their phase difference is constant E. the difference in their frequencies is constant |
|
Answer» D. their phase difference is constant |
|
| 13. |
When a highly coherent beam of light is directed against a very fine wire, the shadow formed behind it is not just that of a single wire but rather looks like the shadow of several parallel wires. The explanation of this involves: A. refraction B. diffraction C. reflection D. the Doppler effect E. an optical illusion |
|
Answer» B. diffraction |
|
| 14. |
When the atmosphere is not quite clear, one may sometimes see colored circles concentric with the Sun or the Moon. These are generally not more than a few diameters of the Sun or Moon and invariably the innermost ring is blue. The explanation for this phenomena involves: A. reflection B. refraction C. interference D. diffraction E. the Doppler effect |
|
Answer» D. diffraction |
|
| 15. |
A light spectrum is formed on a screen using a diffraction grating. The entire apparatus (source, grating and screen) is now immersed in a liquid of refractive index 1.33. As a result, the pattern on the screen: A. remains the same B. spreads out C. crowds together D. becomes reversed, with the previously blue end becoming red E. disappears because the refractive index isn’t an integer |
|
Answer» C. crowds together |
|
| 16. |
No fringes are seen in a single-slit diffraction pattern if: A. the screen is far away B. the wavelength is less than the slit width C. the wavelength is greater than the slit width D. the wavelength is less than the distance to the screen E. the distance to the screen is greater than the slit width |
|
Answer» C. the wavelength is greater than the slit width |
|
| 17. |
A point source of monochromatic light is placed in front of a soccer ball and a screen is placed behind the ball. The light intensity pattern on the screen is best described as: A. a dark disk on a bright background B. a dark disk with bright rings outside C. a dark disk with a bright spot at its center D. a dark disk with a bright spot at its center and bright rings outside E. a bright disk with bright rings outside |
|
Answer» D. a dark disk with a bright spot at its center and bright rings outside |
|
| 18. |
In the equation φ = (2πa/λ) sin θ for single-slit diffraction, φ is: A. the angle to the first minimum B. the angle to the second maximum C. the phase angle between the extreme rays D. Nπ where N is an integer E. (N + 1/2)π where N is an integer |
|
Answer» C. the phase angle between the extreme rays |
|
| 19. |
A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength λ. If the slit width is decreased and no other changes are made: A. the intensity at the center of the pattern decreases and the pattern expands away from the bright center B. the intensity at the center of the pattern increases and the pattern contracts toward the bright center C. the intensity at the center of the pattern does not change and the pattern expands away from the bright center D. the intensity at the center of the pattern does not change and the pattern contracts toward the bright center E. neither the intensity at the center of the pattern nor the pattern itself change |
|
Answer» A. the intensity at the center of the pattern decreases and the pattern expands away from the bright center |
|
| 20. |
The intensity at a secondary maximum of a single-slit diffraction pattern is less than the intensity at the central maximum chiefly because: A. some Huygens wavelets sum to zero at the secondary maximum but not at the central maximum B. the secondary maximum is further from the slits than the central maximum and intensity decreases as the square of the distance C. the Huygens construction is not valid for a secondary maximum D. the amplitude of every Huygens wavelet is smaller when it travels to a secondary maximum than when it travels to the central maximum E. none of the above |
|
Answer» A. some Huygens wavelets sum to zero at the secondary maximum but not at the central maximum |
|
| 21. |
A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength λ. If λ is increased and no other changes are made: A. the intensity at the center of the pattern decreases and the pattern expands away from the bright center B. the intensity at the center of the pattern increases and the pattern contracts toward the bright center C. the intensity at the center of the pattern does not change and the pattern expands away from the bright center D. the intensity at the center of the pattern does not change and the pattern contracts toward the bright center E. neither the intensity at the center of the pattern nor the pattern itself change |
|
Answer» C. the intensity at the center of the pattern does not change and the pattern expands away from the bright center |
|
| 22. |
The reason there are two slits, rather than one, in a Young’s experiment is: A. to increase the intensity B. one slit is for frequency, the other for wavelength C. to create a path length difference D. one slit is for Vector E fields, the other is for Vector B fields E. two slits in parallel offer less resistance |
|
Answer» C. to create a path length difference |
|
| 23. |
In a Young’s double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of: A. a fourth of a wavelength B. a half a wavelength C. a wavelength D. three-fourths of a wavelength E. none of the above |
|
Answer» E. none of the above |
|
| 24. |
At a diffraction line phasors associated with waves from the slits of a multiple-slit barrier: A. are aligned B. form a closed polygon C. form a polygon with several sides missing D. are parallel but adjacent phasors point in opposite directions E. form the arc of a circle |
|
Answer» A. are aligned |
|
| 25. |
If we increase the wavelength of the light used to form a double-slit diffraction pattern: A. the width of the central diffraction peak increases and the number of bright fringes within the peak increases B. the width of the central diffraction peak increases and the number of bright fringes within the peak decreases C. the width of the central diffraction peak decreases and the number of bright fringes within the peak increases D. the width of the central diffraction peak decreases and the number of bright fringes within the peak decreases E. the width of the central diffraction peak increases and the number of bright fringes within the peak stays the same |
|
Answer» E. the width of the central diffraction peak increases and the number of bright fringes within the peak stays the same |
|
| 26. |
For a certain multiple-slit barrier the slit separation is 4 times the slit width. For this system: A. the orders of the lines that appear are all multiples of 4 B. the orders of lines that appear are all multiples of 2 C. the orders of the missing lines are all multiples of 4 D. the orders of the missing lines are all multiples of 2 E. none of the above are true |
|
Answer» C. the orders of the missing lines are all multiples of 4 |
|
| 27. |
The dispersion of a diffraction grating indicates: A. the resolution of the grating B. the separation of lines of the same order C. the number of rulings in the grating D. the width of the lines E. the separation of lines of different order for the same wavelength |
|
Answer» B. the separation of lines of the same order |
|
| 28. |
An air wedge is formed from two glass plates that are in contact at their left edges. There are ten dark bands when viewed by reflection using monochromatic light. The left edge of the top plate is now slowly lifted until the plates are parallel. During this process: A. the dark bands crowd toward the right edge B. the dark bands remain stationary C. the dark bands crowd toward the left edge D. the dark bands spread out, disappearing off the right edge E. the dark bands spread out, disappearing off the left edge |
|
Answer» E. the dark bands spread out, disappearing off the left edge |
|
| 29. |
Yellow light is viewed by reflection from a thin vertical soap film. Let λ be the wavelength of the light within the film. Why is there a large dark space at the top of the film?A. no light is transmitted through this part of the film B. the film thickness there is λ/4 C. the film thickness there is much less than λ D. the film is too thick in this region for thin film formulas to apply E. the reflected light is in the infrared |
|
Answer» C. the film thickness there is much less than λ |
|
| 30. |
Binoculars and microscopes are frequently made with coated optics by adding a thin layer of transparent material to the lens surface as shown. One wants:A. constructive interference between waves 1 and 2 B. destructive interference between waves 3 and 4 C. constructive interference between 3 and 4 D. the coating to be more transparent than the lens E. the speed of light in the coating to be less than that in the lens |
|
Answer» C. constructive interference between 3 and 4 |
|
| 31. |
In a double-slit diffraction experiment the number of interference fringes within the central diffraction maximum can be increased by: A. increasing the wavelength B. decreasing the wavelength C. decreasing the slit separation D. increasing the slit width E. decreasing the slit width |
|
Answer» E. decreasing the slit width |
|
| 32. |
A parallel beam of monochromatic light is incident on a slit of width 2 cm. The light passing through the slit falls on a screen 2 m away. As the slit width is decreased: A. the width of the pattern on the screen continuously decreases B. the width of the pattern on the screen at first decreases but then increases C. the width of the pattern on the screen increases and then decreases D. the width of the pattern on the screen remains the same E. the pattern on the screen changes color going from red to blue |
|
Answer» B. the width of the pattern on the screen at first decreases but then increases |
|
| 33. |
At the second minimum adjacent to the central maximum of a single-slit diffraction pattern the Huygens wavelet from the top of the slit is 180° out of phase with the wavelet from: A. a point one-fourth of the slit width from the top B. the midpoint of the slit C. a point one-fourth of the slit width from the bottom of the slit D. the bottom of the slit E. none of these |
|
Answer» A. a point one-fourth of the slit width from the top |
|
| 34. |
Light of wavelength is normally incident on some plane optical device. The intensity pattern shown is observed on a distant screen (θ is the angle measured from the normal of the device). The device could be:A. a single slit of width W B. a single slit of width 2W C. two narrow slits with separation W D. two narrow slits with separation 2W E. a diffraction grating with slit separation W |
|
Answer» A. a single slit of width W |
|
| 35. |
The spacing between adjacent slits on a diffraction grating is 3λ. The deviation θ of the first order diffracted beam is given by:A. sin(θ/2) = 1/3 B. sin(θ/3) = 2/3 C. sin(θ)=1/3 D. tan(θ/2) = 1/3 E. tan(θ)=2/3 |
|
Answer» C. sin(θ)=1/3 |
|
| 36. |
In a single-slit diffraction pattern, the central maximum is about twice as wide as the other maxima. This is because: A. half the light is diffracted up and half is diffracted down B. the central maximum has both electric and magnetic fields present C. the small angle approximation applies only near the central maximum D. the screen is flat instead of spherical E. none of the above |
|
Answer» E. none of the above |
|
| 37. |
A person with her eye relaxed looks through a diffraction grating at a distant monochromatic point source of light. The slits of the grating are vertical. She sees: A. one point of light B. a hazy horizontal strip of light of the same color as the source C. a hazy strip of light varying from violet to red D. a sequence of horizontal points of light E. a sequence of closely spaced vertical lines |
|
Answer» D. a sequence of horizontal points of light |
|
| 38. |
Huygens’ construction can be used only: A. for light B. for an electromagnetic waveC. if one of the media is vacuum (or air) D. for transverse waves E. for all of the above and other situations |
|
Answer» E. for all of the above and other situations |
|
| 39. |
The widths of the lines produced by monochromatic light falling on a diffraction grating can be reduced by: A. increasing the wavelength of the light B. increasing the number of rulings without changing their spacing C. decreasing the spacing between adjacent rulings without changing the number of rulingsD. decreasing both the wavelength and the spacing between rulings by the same factor E. increasing the number of rulings and decreasing their spacing so the length of the grating remains the same |
|
Answer» B. increasing the number of rulings without changing their spacing |
|
| 40. |
X rays are: A. electromagnetic waves B. negatively charged ions C. rapidly moving electrons D. rapidly moving protons E. rapidly moving neutrons |
|
Answer» A. electromagnetic waves |
|
| 41. |
Bragg’s law for x-ray diffraction is 2d sin θ = mλ, where the quantity d is: A. the height of a unit cell B. the smallest interatomic distance C. the distance from detector to sample D. the distance between planes of atoms E. the usual calculus symbol for a differential |
|
Answer» D. the distance between planes of atoms |
|
| 42. |
In the equation d sin θ = mλ for the lines of a diffraction grating d is: A. the number of slits B. the slit width C. the slit separation D. the order of the line E. the index of refraction |
|
Answer» C. the slit separation |
|
| 43. |
Bragg’s law for x-ray diffraction is 2d sin θ = mλ, where θ is the angle between the incident beam and: A. a reflecting plane of atoms B. the normal to a reflecting plane of atoms C. the scattered beam D. the normal to the scattered beam E. the refracted beam |
|
Answer» A. a reflecting plane of atoms |
|
| 44. |
In a Young’s experiment, it is essential that the two beams: A. have exactly equal intensity B. be exactly parallel C. travel equal distances D. come originally from the same source E. be composed of a broad band of frequencies |
|
Answer» D. come originally from the same source |
|
| 45. |
In an experiment to measure the wavelength of light using a double slit, it is found that the fringes are too close together to easily count them. To spread out the fringe pattern, one could: A. decrease the slit separation B. increase the slit separation C. increase the width of each slit D. decrease the width of each slit E. none of these |
|
Answer» A. decrease the slit separation |
|
| 46. |
In a Young’s double-slit experiment, the slit separation is doubled. This results in: A. an increase in fringe intensity B. a decrease in fringe intensity C. a halving of the wavelength D. a halving of the fringe spacing E. a doubling of the fringe spacing |
|
Answer» D. a halving of the fringe spacing |
|
| 47. |
Light from a small region of an ordinary incandescent bulb is passed through a yellow filter and then serves as the source for a Young’s double-slit experiment. Which of the following changes would cause the interference pattern to be more closely spaced? A. Use slits that are closer together B. Use a light source of lower intensity C. Use a light source of higher intensity D. Use a blue filter instead of a yellow filter E. Move the light source further away from the slits. |
|
Answer» D. Use a blue filter instead of a yellow filter |
|
| 48. |
Waves from two slits are in phase at the slits and travel to a distant screen to produce the third side maximum of the interference pattern. The difference in the distance traveled by the waves is: A. half a wavelength B. a wavelength C. three halves of a wavelength D. two wavelengths E. three wavelengths |
|
Answer» E. three wavelengths |
|
| 49. |
Waves from two slits are in phase at the slits and travel to a distant screen to produce the second minimum of the interference pattern. The difference in the distance traveled by the waves is: A. half a wavelength B. a wavelength C. three halves of a wavelength D. two wavelengths E. five halves of a wavelength |
|
Answer» C. three halves of a wavelength |
|