Physics Final Review

Which of the following changes would increase the separation between the bright fringes in the diffraction pattern formed by a diffraction grating? A) Immerse the apparatus in water. B) Increase the separation between the slits. C) Increase the wavelength of the light used. D) None of these. E) More than one of these. (*Ch. 26*)

Increase the wavelength of the light used.

Why do heavy nuclei contain more neutrons than protons? A) Neutrons are heavier than protons. B) Neutrons are lighter than protons. C) Neutrons are radioactive, and so are heavy nuclei. D) Neutrons dilute the electric repulsion of the protons. (*Ch. 30*)

Neutrons dilute the electric repulsion of the protons.

Modern nuclear bomb tests have created an extra high level of 14C in our atmosphere. When future archaeologists date samples from this era, without knowing of this testing, will their dates be too young? Too old? Correct? If correct, why? A) Too young. B) Too old. C) Correct, since 14C from bomb tests is different from that produced naturally. D) Correct, because modern biological materials do not gather 14C from bomb tests. (*Ch. 30*)

Too young.

An oil film (n = 1.48) of thickness 290 nm floating on water is illuminated with white light at normal incidence. What is the wavelength of the dominant color in the reflected light? A) Yellow (572 nm) B) Blue (470 nm) C) Blue-green (493 nm) D) Violet (404 nm) E) Green (541 nm) (*Ch. 26*)

Yellow (572 nm)

A radioactive nuclide of atomic number Z emits an electron, then the daughter nuclide emits a gamma ray. What is the atomic number of the resulting nuclide after both processes? A) Z+1 B) Z-1 C) Z-2 D) Z-3 (*Ch. 30*)

Z+1

A radioactive nuclide of atomic number Z emits an alpha particle and the daughter nucleus then emits a beta particle. What is the atomic number of the resulting nuclide? A) Z-1 B) Z+1 C) Z-2 D) Z-3 (*Ch. 30*)

Z-1

Estimate the mass of a nucleus with radius 2.80 × 10-15 m. A) About 2.29 × 10-26 kg B) About 2.11 × 10-26 kg C) About 7.53 × 10-27 kg D) About 4.72 × 10-26 kg (*Ch. 30*)

About 2.11 × 10-26 kg

Estimate the radius of a nucleus with mass 50 atomic mass units. A) About 3.68 × 10-15 m B) About 8.49 × 10-15 m C) About 6.17 × 10-15 m D) About 4.42 × 10-15 m (*Ch. 30*)

About 4.42 × 10-15 m

About how many days are required for a radioactive sample, with an initial activity of 105 Bq, to decay to an activity of 100 Bq? The half-life of the material is 4.5 days. A) About 36 days B) About 54 days C) About 45 days D) About 31 days

About 45 days

A stable nucleus contains many protons very close to each other, all positively charged. Why do the protons not fly apart due to mutual Coulomb repulsion? A) Attractive nuclear forces in the nucleus counteract the effect of the Coulomb forces. B) There are an equal number of electrons in the nucleus which neutralize the protons. C) The Coulomb force does not operate within nuclei. D) The neutrons in the nucleus shield the protons from each other. (*Ch. 30*)

Attractive nuclear forces in the nucleus counteract the effect of the Coulomb forces.

Which of the following is not true of the nuclear force? A) The nuclear force does not depend on charge. B) For two protons in close proximity, the nuclear force and the electric force have comparable magnitudes. C) A nucleon in a large nucleus interacts via the nuclear force only with nearby nucleons, not with ones far away in the nucleus. D) The nuclear force has a short range, of the order of nuclear dimensions. E) The nuclear force favors binding of pairs of protons or neutrons with opposite spin angular momenta. (*Ch. 30*)

For two protons in close proximity, the nuclear force and the electric force have comparable magnitudes.

A camera used for aerial surveillance has a lens with a 30 cm maximum aperture and a 42 cm focal length. Assume light of 550 nm wavelength is used and that the resolution of the camera is limited solely by diffraction. The angular resolution of the camera at maximum aperture, in mrad, is closest to: A) 1.6 B) 2.2 C) 3.2 D) 4.5 E) 6.3 (*Ch. 26*)

2.2

The image of a tree on a 35 mm color slide is 1.7 mm high. It is to be projected onto a screen 8.0 m from the slide, and is to appear 559 mm high. (a) What focal length lens (in meters) is needed? (b) What is the distance in meters between the lens and the slide? (c) What is the magnification of the system? A) (a) 0.02 m (b) 0.02 m (c) 329 B) (a) 0.02 m (b) -8.02 m (c) 0.00 C) (a) 0.02 m (b) -0.02 m (c) 0.00 D) (a) 0.02 m (b) 7.98 m (c) 0.00 (*Ch. 25*)

(a) 0.02 m (b) 0.02 m (c) 329

A farsighted boy has a near point at 2.3 m and requires eyeglasses to correct his vision. Corrective lenses are available in increments in power of 0.25 diopters. The eyeglasses should have lenses of the lowest power for which the near point is no further than 25 cm. The correct choice of lens power for eyeglasses, in diopters, is: A) +3.75 B) +4.00 C) +3.50 D) +4.25 E) +3.25 (*Ch. 25*)

+3.75 tip: farsighted = converging lenses and reason it isn't 3.5 is because that is not enough power, even if it is only slightly, we have to overcompensate to the next 0.25 diopter increment

As a treatment for cataracts (a cloudiness of the lens of the eye), the natural lens is removed and a plastic lens is implanted. After this is done a person can see distant objects clearly, but he cannot accommodate to focus on nearby objects. If for example such a person wanted to read a book at a distance of 25 cm, he would have to wear eyeglasses whose diopter power was approximately A) +2.78 diopters B) +3.33 diopters C) +4.00 diopters D) -4.00 diopters E) -1.78 diopters (*Ch. 25*)

+4.00 diopters

The objective and the eyepiece of a microscope have focal lengths of 4.0 mm and 25 mm, respectively. The objective produces a real image 30 times the size of the object. The final image is viewed at infinity. The near point of the microscope user is at 25 cm. In Situation 25.2, the distance between the object and the focal point of the objective, in mm, is closest to: A) 0.18 B) 0.13 C) 0.28 D) 0.33 E) 0.23 (*Ch. 25*)

0.13

(*) The objective and the eyepiece of a microscope have focal lengths of 4.0 mm and 25 mm, respectively. The objective produces a real image 30 times the size of the object. The final image is viewed at infinity. The near point of the microscope user is at 25 cm. The distance between the object and the focal point of the objective, in mm, is closest to: A) 0.13 B) 0.18 C) 0.23 D) 0.28 E) 0.33 (*Ch. 25*)

0.13 mm

The angular magnification of a refracting telescope is 40. When the object and final image are both at infinity, the distance between the eyepiece and the objective is 143.5 cm. The telescope is used to view a distant radio tower. The real image of the tower, formed by the objective, is 6.0 mm in height. The focal point of the eyepiece is positioned at the real image. In Situation 25.3, the angle subtended by the final image of the tower is closest to: A) 0.21 rad B) 0.23 rad C) 0.17 rad D) 0.15 rad E) 0.19 rad (*Ch. 25*)

0.17

A 0.85 mm diameter hole is illuminated by infrared light of wavelength 2.5 μm What is the angle of the first dark fringe? A) 1.2 × 10-2 degrees B) 4.8 × 10-2 degrees C) 0.21 degrees D) 3.6 × 10-3 degrees (*Ch. 26*)

0.21 degrees

(*) Light of wavelength 560 nm illuminates a single slit placed 60 cm from a screen. The 28) separation between the first and third minima in the diffraction pattern is 2.8 mm. What is the slit width? A) 1.16 mm B) 0.72 mm C) 3.8 × 10-5 m D) 0.082 mm E) 0.24 mm (*Ch. 26*)

0.24 mm

A pair of narrow slits, separated by 1.8 mm, is illuminated by a monochromatic light source. Light waves arrive at the two slits in phase. A fringe pattern is observed on a screen 4.8 m from the slits. In Situation 26.2, monochromatic light of 450 nm wavelength is used. The angular separation between adjacent dark fringes on the screen, measured at the slits, in m rad, is closest to: A) 0.30 B) 0.20 C) 0.15 D) 0.25 E) 0.36 (*Ch. 26*)

0.25 tip, from last step in pic, just convert to *m rad*

(*) The maximum permissible workday dose for occupational exposure to radiation is 18 mrem. A 54 kg laboratory technician absorbs 2.6 mJ of 0.3 MeV gamma rays in a work day. The relative biological efficiency (RBE) for gamma rays is 1.00. The ratio of the equivalent dosage received by the technician to the maximum permissible equivalent dosage is closest to: A) 0.27 B) 0.29 C) 0.32 D) 0.35 E) 0.37 (*Ch. 30*)

0.27

Certain planes of a crystal of halite have a spacing of 0.399 mm. The crystal is irradiated by a beam of x-rays. First order constructive interference occurs when the beam makes an angle of 20° with the planes. In Situation 26.5, the wavelength of the x-rays, in nm, is closest to: A) 0.24 B) 0.21 C) 0.17 D) 0.27 E) 0.14 (*Ch. 26*)

0.27

The lattice spacing of the principal Bragg planes in sodium chloride is 0.282 nm. For what wavelength will the first order diffracted beam be deviated by 70°? A) 0.530 nm B) 0.323 nm C) 0.680 nm D) 0.150 nm E) 0.662 nm (*Ch. 26*)

0.323 nm

(*) A myopic girl wears eyeglasses that allow her to have clear distant vision. The power of the lenses of her eyeglasses is -3.00 diopters. Without eyeglasses, the far point of the girl is closest to: A) 0.33 m B) 0.25 m C) 0.17 m D) 0.42 m E) 0.50 m (*Ch. 25*)

0.33 m

A myopic girl wears eyeglasses that allow her to have clear distant vision. The power of the lenses of her eyeglasses is -3.00 diopters. Without eyeglasses, the far point of the girl is closest to: A) 0.25 m B) 0.50 m C) 0.17 m D) 0.33 m E) 0.42 m (*Ch. 25*)

0.33 m

A camera set with f-number f/4 has a focal length of 50 nm. What is the minimum spacing of two objects positioned 12 meters from the lens if the objects are barely resolved in the image? Assume the light wavelength is 500 nm. A) 4.9 × 10-5 m B) 0.58 mm C) 1.66 mm D) 0.024 mm E) 4.72 mm (*Ch. 26*)

0.58 mm

A lens of focal length 45 mm is used as a magnifier. The object being viewed is 6.8 mm long, and is positioned at the focal point of the lens. The lens is moved closer to the object, so that the image is now 25 cm from the lens. The distance the lens has been moved, in cm, is closest to: A) 0.62 B) 0.48 C) 0.76 D) 0.69 E) 0.55 (*Ch. 25*)

0.69 *magnifiers create upright, virtual images!

(*) The objective and the eyepiece of a refracting astronomical telescope have focal lengths of 320 cm and 4.0 cm, respectively. The telescope is used to view Neptune and the final image is set at infinity. The diameter of Neptune is 4.96 × 10⁷ m and the distance from Earth at the time of observation is 4.4 × 10¹² m. The angle subtended by the final telescopic image of Neptune, in m rad, is closest to: A) 0.9 B) 1.1 C) 1.3 D) 1.5 E) 1.7 (*Ch. 25*)

0.9 m rad

A single slit with width 644 nm is illuminated with light of wavelength 796 nm. How many minima occur in the angular range from θ = 0° to θ = ±38°? A) 0.79 minima B) 0.5 minima C) 1 minima D) 1.52 minima (*Ch. 26*)

1 minima

The following masses are known: 1 n 0 --> 1.008665 u 1 H 1 --> 1.007825 u 222 Rn 86 --> 222.017571 u The binding energy of 222Rn, in MeV, is closest to: A) 2,300 B) 2,400 C) 2,100 D) 1700 E) 1900

1,700

How much energy is released when 0.600 μg of 3H have decayed to 3He? Use 1 u = 931.494 MeV/c2, M(3He) = 3.01493 u, and M(3H) = 3.01550 u. A) 3.41 × 103 J B) 5.12 × 103 J C) 1.02 × 104 J D) 3.07 × 104 J (*Ch. 30*)

1.02 × 104 J

(*) The decay constant of a radioactive nuclide is 1.6 × 10-3 s-1. At a given instant, the number of atoms of the radioactive nuclide is 1.85 × 1012. The number of atoms of the nuclide that remain after a time interval of 30 minutes is closest to: A) 1.14 × 1011 B) 1.26 × 1011 C) 1.04 × 1011 D) 1.52 × 1011 E) 1.38 × 1011 (*Ch. 30*)

1.04 × 1011

In a 35 mm single lens reflex camera (SLR) the distance from the lens to the film is varied in order to focus on objects at varying distances. Over what range must a lens of 45 mm focal length vary if the camera is to be able to focus on objects ranging in distance from infinity down to 1.4 m from the camera? A) 5.98 mm B) 4.48 mm C) 1.20 mm D) 1.49 mm E) 2.09 mm (*Ch. 25*)

1.49 mm

A metallic sheet has a large number of slits, 5.0 mm wide and 20 cm apart, and is used as a diffraction grating for microwaves. A wide parallel beam of microwaves is incident normally on the grating. In Situation 26.4, the smallest microwave frequency for which only the central maximum occurs is closest to: A) 1.5 GHz B) 1.0 GHz C) 2.0 GHz D) 0.5 GHz E) 0.7 GHz (*Ch. 26*)

1.5 GHz

(*) A nuclear bomb explosion results in a mass decrease of about 2.10 g, between the initial and the final ingredients. How much energy is released? A) 1.89 × 1013 J B) 6.30 × 105 J C) 2.25 × 1012 J D) 1.89 × 1014 J (*Ch. 30*)

1.89 × 1014 J

At most, how many bright fringes can be formed on one side of the central bright fringe (not counting the central bright fringe) when light of 625 nm falls on a double slit whose spacing is 6.77 x 10-6 m? A) 11 B) 9 C) 12 D) 8 E) 10 (*Ch. 26*)

10

Two optically flat glass plates, 16 cm long, are in contact at one end and separated by 0.020 mm at the other end. The space between the plates is occupied by oil with index of refraction 1.45. The index of the glass plates is 1.55. The plates are illuminated at normal incidence with monochromatic light, and fringes are observed. In Situation 26.3, the monochromatic light has a wavelength of 580 nm. The number of bright fringes which are visible is closest to: A) 80 B) 70 C) 60 D) 90 E) 100 (*Ch. 26*)

100

A lens of focal length 90 mm is used as a magnifier. The object being viewed is 9.9 mm long, and is positioned at the focal point of the lens. The angle subtended by the image at infinity, in milliradians, is closest to: A) 110 B) 147 C) 37 D) 183 E) 73 (*Ch. 25*)

110 m rad *tip: convert to cm. Original equations: 1) M = 25 cm/f 2) θ = y/25 cm θ' is the angle subtended *with* a magnifier θ is the angle subtended *without* a magnifier ^hence, we used this equation for the second step

The objective of a microscope has a focal length of 2.4 mm and the eyepiece has an angular magnification of 15. The object is positioned 0.06 mm beyond the focal point of the objective. The focal point of the eyepiece is positioned at the real image formed by the objective. In Situation 25.1, the separation between the objective and the eyepiece, in mm, is 16) closest to: A) 98 B) 107 C) 102 D) 111 E) 115 (*Ch. 25*)

115

A machinist with normal vision has a near point at 25 cm. The machinist wears eyeglasses in order to do close work. The power of the lenses is +4.25 diopters. With these eyeglasses, the near point of the machinist, in cm, is closest to: A) 7 B) 17 C) 15 D) 12 E) 10 (*Ch. 25*)

12

The objective and the eyepiece of a microscope have focal lengths of 4.0 mm and 25 mm, respectively. The objective produces a real image 30 times the size of the object. The final image is viewed at infinity. The near point of the microscope user is at 25 cm. In Situation 25.2, the distance between the objective and the real image produced by it, in mm, is closest to: A) 128 B) 120 C) 116 D) 132 E) 124 (*Ch. 25*)

124

Two radio antennas are 120 m apart on a north-south line. The two antennas radiate in phase at a frequency of 5.6 MHz. All radio measurements are made far from the antennas. The smallest angle, reckoned north of east from the antennas, at which destructive interference of the two radio waves occurs, is closest to: A) 9.7° B) 13° C) 16° D) 6.4° E) 19° (*Ch. 26*)

13°

The angular magnification of a refracting telescope is 40. When the object and final image are both at infinity, the distance between the eyepiece and the objective is 143.5 cm. The telescope is used to view a distant radio tower. The real image of the tower, formed by the objective, is 6.0 mm in height. The focal point of the eyepiece is positioned at the real image. In Situation 25.3, the focal length of the objective, in cm, is closest to: A) 140 B) 141 C) 139 D) 137 E) 138 (*Ch. 25*)

140

Light of wavelength 500 nm illuminates a 0.50 mm diameter hole. A screen is placed 6.0 m behind the slit. What is the width of the central maximum on the screen? A) 3,700 μm B) 15 mm C) 260 μm D) 7.3 mm (*Ch. 26*)

15 mm

Astronomers are proud of their telescopes, and often say they can "resolve a dime at so many miles." How many miles can you move a disk (D = 3.0 cm) from a 102-cm-diameter telescope mirror and just resolve it using light of wavelength 389 nm? A) 40 mi B) 9.7 mi C) 19 mi D) 190,000,000 mi (*Ch. 26*)

19 mi

In a head-on collision, an alpha particle (Z = 2) of energy 8.20 MeV bounces straight back from a nucleus of charge 80.0 e. How close were the centers of the objects at closest approach? A) 2.17×10-14m B)6.56×10-15m C) 2.81×10-14m D) 3.39×10-12m (*Ch. 30*)

2.81×10-14m

A 35 mm camera equipped with a 40 mm focal length lens is used to photograph a tree 17 m tall. The aperture of the lens is set at f/8. A 32 mm high image of the tree on the film is required. The required distance, between the tree and the camera, to take the photograph is closest to: A) 22 m B) 23 m C) 26 m D) 24 m E) 21 m (*Ch. 25*)

21 m

(*) A 35mm camera is equipped with a 45 mm focal length lens is used to photograph a tree 15 m tall. The aperture of the lens is set at f/2. The aperture diameter at f/2, in mm, is closest to: A) 23 B) 14 C) 18 D) 27 E) 32 (*Ch. 25*)

23 mm

(*) A lens of focal length 45 mm is mounted on a 35 mm camera. The lens aperture is set at f/2 and the shutter speed set at ¹⁄²⁰⁰⁰ s. The aperture diameter, in mm, is closest to: A) 23 B) 16 C) 19 D) 26 E) 29 (*Ch. 25*)

23 mm

A summary of the nuclear reactions that power our sun can be written as 4p → 4He + 2e-, with masses of 938.272 MeV/c2 for p, 3727.38 MeV/c2 for helium, and 0.511 MeV/c2 for electrons. If this is the reaction that occurs, how much energy is released? A) 28.3 MeV B) 279.01 MeV C) 2790.13 MeV D) 24.69 MeV (*Ch. 30*)

24.69 MeV

(*) A single slit forms a diffraction pattern, with the first minimum at an angle of 40° from central maximum. Monochromatic light of 410 nm wavelength is used. The same slit, illuminated by a different monochromatic light source, produces a diffraction pattern with the second minimum at a 60° angle from the central maximum. The wavelength of this light, in nm, is closest to: A) 326 B) 342 C) 309 D) 293 E) 276 (*Ch. 26*)

276

The maximum permissible workday dose for occupational exposure to radiation is 11 mrem. A 77 kg laboratory technician absorbs 2.3 mJ of 0.5 MeV gamma rays in a work day. The relative biological efficiency (RBE) for gamma rays is 1.00. The number of gamma-ray photons absorbed by the technician in a workday is closest to: A) 3 × 109 B) 1 × 109 C) 3 × 1010 D) 3 × 108 E) 1 × 108

3 × 1010

The spacing of ruled lines on a diffraction grating is 1,900 nm. The grating is illuminated at normal incidence with a parallel beam of white light in the 400 nm to 700 nm wavelength band. The angular width of the gap between the first order spectrum and the second order spectrum is closest to: A) 4.3° B) 2.3° C) 3.3° D) 5.3° E) 6.3° (*Ch. 26*)

3.3°

Redshift measurements on a constellation show that it is receding with a velocity of 7,240 km/s. How far away is the galaxy if Hubble's constant has the value 2.11 × 10-18 s-1? A) 2.0 × 1022 m B) 4.1 × 1023 m C) 1.2 × 1024 m D) 3.4 × 1024 m E) 1.2 × 1026 m (*Ch. 30*)

3.4 × 1024 m

The diameter of an atom is 1.4 × 10-10 m and the diameter of its nucleus is 1.0 × 10-14 m. What fraction of the atom's volume is occupied by mass? A) 5.1 × 10-9 B) 2.6 × 10-17 C) 3.6 × 10-13 D) 7.1 × 10-5 (*Ch. 30*)

3.6 × 10-13

The objective and the eyepiece of a microscope have focal lengths of 4.0 mm and 25 mm, respectively. The objective produces a real image 30 times the size of the object. The final image is viewed at infinity. The near point of the microscope user is at 25 cm. In Situation 25.2, the overall magnification of the microscope is closest to: A) 350 B) 250 C) 450 D) 300 E) 400 (*Ch. 25*)

300

A farsighted boy has a near point at 2.0 m and requires eyeglasses to correct his vision. Corrective lenses are available in increments in power of 0.25 diopters. The eyeglasses should have lenses of the lowest power for which the near point is no further than 25 cm. The boy borrows eyeglasses that have a power of +2.75 diopters. With these eyeglasses, the near point of the boy, in cm, is closest to: A) 37 B) 31 C) 33 D) 40 E) 28 (*Ch. 25*)

31

A grating with 396 lines/mm is illuminated with light of wavelength 343 nm. What is the angular separation between the two lines formed in order m = 2? A) 32.9° B) 15.8° C) 31.5° (*Ch. 26*)

31.5°

What is the angular separation of two spectral lines of wavelengths 497 nm and 251 nm formed in order m = 3 with a 587 line/mm grating? A) 0° B) 24.82° C) 34.84° (*Ch. 26*)

34.84°

A 17 mm wide diffraction grating has rulings of 530 lines per mm. Light is incident 22) normally on the grating. The longest wavelength that forms an intensity maximum in the fifth order is closest to: A) 427 nm B) 452 nm C) 377 nm D) 352 nm E) 402 nm (*Ch. 26*)

377 nm

A 2-slit arrangement with 60.3 μm separation between the slits is illuminated with 537.0 nm light. Assuming that a viewing screen is located 2.14 m from the slits, find the distance from the first dark fringe on one side of the central maximum to the second dark fringe on the other side. A) 26.9 mm B) 76.3 mm C) 38.1 mm D) 57.2 mm (*Ch. 26*)

38.1 mm

A single slit forms a diffraction pattern with monochromatic light. The fourth minimum of the pattern occurs at an angle of 32° from the central maximum. The angle at which the fifth minimum of the pattern occurs is closest to: A) 42.0° B) 42.5° C) 41.0° D) 40.5° E) 41.5° (*Ch. 26*)

41.5°

A 360 nm thick oil film floats on the surface of the water. The indices of refraction of the oil and the water are 1.50 and 1.33, respectively. The surface of the oil is illuminated from above at normal incidence with white light. In Situation 26.1, the two wavelengths of light in the 400 nm to 800 nm wavelength band that are most strongly reflected, in nm, are closest to: A) 430 and 720 B) 450 and 740 C) 410 and 700 D) 490 and 780 E) 470 and 760 (*Ch. 26*)

430 and 720

Certain planes of a crystal of halite have a spacing of 0.399 mm. The crystal is irradiated by a beam of x-rays. First order constructive interference occurs when the beam makes an angle of 20° with the planes. In Situation 26.5, the angle the beam makes with the planes for second order constructive interference to occur is closest to: A) 37° B) 40° C) 43° D) 46° E) 49° (*Ch. 26*)

43°

A single slit, 1,400 nm wide, forms a diffraction pattern when illuminated by monochromatic light of 490 nm wavelength. The largest angle from the central maximum at which the intensity is zero is closest to: A) 38° B) 41° C) 35° D) 44° E) 32° (*Ch. 26*)

44°

An 18 mm wide diffraction grating has rulings of 710 lines per mm. Light is incident normally on the grating. Monochromatic light of 506 nm wavelength is used. The largest angle from the normal at which an intensity maximum is formed is closest to: A) 42° B) 46° C) 40° D) 38° E) 44° (*Ch. 26*)

46°

Two radio antennas are 10 km apart on a north-south axis on a seacoast. The antennas broadcast identical AM radio signals, in phase, at a frequency of 4.70 MHz. A steamship, 200 km offshore, travels due north at a speed of 15 km/hr and passes east of the antennas. A radio on board the ship is tuned to the broadcast frequency. The reception of the radio signal on the ship is a maximum at a given instant. The time interval until the next occurrence of maximum reception is closest to: A) 5.1 min B) 6.4 min C) 7.7 min D) 3.8 min E) 8.9 min (*Ch. 26*)

5.1 min

Two radio antennas are 130 m apart on a north-south line. The two antennas radiate in 1) phase at a frequency of 3.6 MHz. All radio measurements are made far from the antennas. The smallest angle, reckoned east of north from the antennas, at which constructive interference of two radio waves occurs, is closest to: A) 40° B) 35° C) 45° D) 50° E) 55° (*Ch. 26*)

50° tip*: have to use cos or subtract 40 from 90 degrees. Arccos(83m/130m)= 50.15 degrees or subtract 90-40= 50. 40 degrees is the refrence angle. Keyword is "east of north"

A 360 nm thick oil film floats on the surface of the water. The indices of refraction of the oil and the water are 1.50 and 1.33, respectively. The surface of the oil is illuminated from above at normal incidence with white light. In Situation 26.1, the wavelength of light in the 400 nm to 800 nm wavelength band that is most weakly reflected, in nm, is closest to: A) 540 B) 560 C) 600 D) 580 E) 520 (*Ch. 26*)

540

Light from a He-Ne laser of wavelength 633 nm passes through a circular aperture. It is observed on a screen 4.0 m behind the aperture. The width of the central maximum is 1.1 cm. What is the diameter of the hole? A) 4,700 μm B) 560 μm C) 32,000 μm D) 9.8 μm (*Ch. 26*)

560 μm

The spacing of ruled lines on a diffraction grating is 1,770 nm. The grating is illuminated at normal incidence with a parallel beam of white light in the 400 nm to 700 nm wavelength band. The longest wavelength that appears in the third order spectrum is closest to: A) 590 nm B) 550 nm C) 610 nm D) 530 nm E) 570 nm (*Ch. 26*)

590 nm

A lens of focal length 40 mm is used as a magnifier. The object being viewed is 5.3 mm long, and is positioned at the focal point of the lens. The user of the magnifier has a near point at 25 cm. The angular magnification of the magnifier is closest to: A) 7.5 B) 8.1 C) 6.9 D) 6.3 E) 5.6 (*Ch. 25*)

6.3

An astronomical telescope is made from two lenses: the objective lens has a focal length of f = 114 cm, and the eyepiece lens has a focal length of f = 17.0 cm. (b) What is the angular magnification of the telescope? A) (a) 131 cm (b) 6.71 (c) 0.15 B) (a) 194 cm (b) 1.18 (c) 0.85 C) (a) 97 cm (b) 0.15 (c) 6.71 D) (a) 262 cm (b) 0.87 (c) 1.15 (*Ch. 25*)

6.71

A double slit illuminated with light of wavelength 644 nm forms a diffraction pattern on a screen 6 cm away. The slit separation is d = 2,783 nm. What is the distance Δx between orders m = 14 and m = 9? A) 3.47×107 nm B) 6.94×107 nm C) 129.64 × 107 nm D) 13.88 × 107 nm (*Ch. 26*)

6.94×107 nm

The objective of a microscope has a focal length of 2.4 mm and the eyepiece has an angular magnification of 15. The object is positioned 0.06 mm beyond the focal point of the objective. The focal point of the eyepiece is positioned at the real image formed by the objective. In Situation 25.1, the overall magnification of the microscope is closest to: A) 500 B) 400 C) 600 D) 550 E) 450 (*Ch. 25*)

600

(*) The objective lens of an astronomical telescope has a focal length of 60 cm and the eyepiece has a focal length of 2 cm. How far apart should the lenses be placed in order to form a final image at infinity? A) 44 cm B) 58 cm C) 76 cm D) 60 cm E) 62 cm (*Ch. 25*)

62 cm

A metallic sheet has a large number of slits, 5.0 mm wide and 20 cm apart, and is used as a diffraction grating for microwaves. A wide parallel beam of microwaves is incident normally on the grating. In Situation 26.4, the microwave wavelength is 6.0 cm. The largest angle from the normal, at which an intensity maximum occurs, is closest to: A) 74° B) 84° C) 64° D) 69° E) 79° (*Ch. 26*)

64°

(*) An optical engineer needs to ensure that the bright fringes from a double-slit are 15.7 mm apart on a detector that is 1.70 m from the slits. If the slits are illuminated with 633 nm light, how far apart should the slits be? A) 79.5 μm B) 63.0 μm C) 68.5 μm D) 74.0 μm (*Ch. 26*)

68.5 μm

A metallic sheet has a large number of slits, 5.0 mm wide and 20 cm apart, and is used as a diffraction grating for microwaves. A wide parallel beam of microwaves is incident normally on the grating. In Situation 26.4, intensity maxima occur two degrees apart in the central region. The wavelength of the microwaves is closest to: A) 5 mm B) 6 mm C) 7 mm D) 8 mm E) 9 mm (*Ch. 26*)

7 mm

The eyepiece of a compound microscope has a focal length of 2.50 cm and the objective has a focal length of 1.60 cm. The two lenses are separated by 14.0 cm. The microscope is used by a person with normal eyes (near point at 25 cm). What is the angular magnification of the microscope? A) 88 B) 219 C) 115 D) 72 E) 180 (*Ch. 25*)

72

Two optically flat glass plates, 16 cm long, are in contact at one end and separated by 0.020 mm at the other end. The space between the plates is occupied by oil with index of refraction 1.45. The index of the glass plates is 1.55. The plates are illuminated at normal incidence with monochromatic light, and fringes are observed. In Situation 26.3, the spacing of the dark fringes is 2.0 mm. The wavelength of the monochromatic light, in nm, is closest to: A) 475 B) 725 C) 525 D) 425 E) 675 (*Ch. 26*)

725

(*) A pair of narrow slits, separated by 1.8 mm, is illuminated by a monochromatic light source. Light waves arrive at the two slits in phase. A fringe pattern is observed on a screen 4.8 m from the slits. In Situation 26.2, there are 5.0 bright fringes/cm on the screen. The wavelength of the monochromatic light is closest to: A) 550 nm B) 650 nm C) 750 nm D) 700 nm E) 600 nm (*Ch. 26*)

750 nm

A single slit forms a diffraction pattern, with the first minimum at an angle of 40° from central maximum. Monochromatic light of 530 nm wavelength is used. The width of the slit, in nm, is closest to: A) 689 B) 825 C) 757 D) 791 E) 723 (*Ch. 26*)

825

A simple camera lens with focal object length f₀ = 3.00 cm perfectly focuses the image of an object on a photographic film located a distance 14.00 cm away from the lens. The object now moves away from the lens and the new focal distance is 13.00 cm. (a) How far did the object move? (b) What is the new magnification? A) (a) 12.22 cm (b) 4.33 B) (a) 0.08 cm (b) 3.33 C) (a) 0.03 cm (b) 0.30 D) (a) 990.00 cm (b) 0.23 (*Ch. 25*)

a) 0.08 cm b) 3.33

A lens of focal length 40 mm is mounted on a 35 mm camera. The lens aperture is set at f/5.6 and the shutter speed set at 1/250 s. A different camera has a lens of focal length 56 mm in place. The shutter speed is set at 1/60 s. The lens aperture setting, for the closest matching film exposure, is: A) f/11 B) f/22 C) f/8 D) f/16 E) f/5.6 (*Ch. 25*)

f/16

The attractive force between quarks is mediated by particles called A) chromons B) stickons C) adhesivons D) gluons. E) forcons. (*Ch. 30*)

gluons.

In massive stars, three helium atoms fuse together, forming a carbon nucleus. This reaction heats the core of the star. The net mass of the three helium nuclei must therefore be A) higher than that of the carbon nucleus. B) the same as that of the carbon nucleus (mass is always conserved). C) less than that of the carbon nucleus (*Ch. 30*)

higher than that of the carbon nucleus.

A diffraction grating has 450 lines per mm. What is the highest order that contains the 31) entire visible spectrum from 400 nm to 700 nm? A) m = 4 B) m = 3 C) m = 5 D) m = 6 E) m = 2 (*Ch. 26*)

m = 3

Suppose the half-life of some element is 2 days. If you purchase 10 grams of the element (which was produced in a laboratory 4 days ago), how much of this element would you have 3 days after you purchased it? A) more than 2.5 grams but less than 5 grams B) 2.5 grams C) more than 1.25 grams but less than 2.5 grams D) 1.25 grams E) less than 1.25 grams (*Ch. 30*)

more than 1.25 grams but less than 2.5 grams

Nuclei that are all isotopes of an element all have the same A) number of nucleons. B) number of neutrons. C) mass. D) number of protons. (*Ch. 30*)

number of protons.

Cameras create ___________ images. (*Ch. 25*)

real *positive image distance

The primary reason very large nuclei are unstable is due to A) the repulsive force between the neutrons and the protons. B) the cumulative repulsive force amongst the protons. C) the cumulative attractive force between the protons and the orbiting electrons. (*Ch. 30*)

the cumulative repulsive force amongst the protons.

In a compound microscope A) both the objective and the eyepiece form real images. B) magnification is provided by the objective lens and not by the eyepiece. The eyepiece merely increases the resolution of the image viewed. C) The magnification is m1 + M2, where m1 is the lateral magnification of the objective and M2 is the angular magnification of the eyepiece. D) magnification is provided by the objective and not by the eyepiece. The eyepiece merely increases the brightness of the image viewed. E) the image of the objective serves as the object for the eyepiece. (*Ch. 25*)

the image of the objective serves as the object for the eyepiece.

Neutrons are slightly more massive than protons. If the mass of a neutron were smaller than its actual value, yet still more massive than a proton, a nucleus with a very high atomic number would most likely contain A) fewer neutrons than the actual number. B) more neutrons than the actual number. C) the same number of neutrons as the actual number. (*Ch. 30*)

the same number of neutrons as the actual number.

Magnifiers create ____________ images. (*Ch. 25*)

virtual *negative image distance, but they are converging lenses being used to create virtual images, so focal length is positive