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| 1 | Although earlier scientists believed light was transmitted by particles, it is now established that light is a wave phenomenon. |
 | A) | True |
| B) | False |
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| 2 | Infrared rays are more energetic than visible or ultraviolet rays. |
| A) | True |
| B) | False |
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| 3 | Interference of light waves is explained more easily on the basis of the wave theory of light. |
| A) | True |
| B) | False |
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| 4 | The propagation of light through outer space is possible because of the presence of a light-carrying ether. |
| A) | True |
| B) | False |
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| 5 | The Michelson-Morley experiment demonstrated that the velocity of light is a constant, independent of the motion of the source. |
| A) | True |
| B) | False |
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| 6 | The nanometer is 10 times as large as the angstrom. |
| A) | True |
| B) | False |
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| 7 | The energy of light is directly proportional to the wavelength. |
| A) | True |
| B) | False |
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| 8 | The first successful terrestrial measurement of the speed of light was made by Fizeau. |
| A) | True |
| B) | False |
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| 9 | The photoelectric effect occurs when light is emitted as a result of electron bombardment. |
| A) | True |
| B) | False |
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| 10 | The nature of light is no different fundamentally from the nature of heat radiation. |
| A) | True |
| B) | False |
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| 11 | One lumen of red light does not represent the same luminous flux as one lumen of blue light. |
| A) | True |
| B) | False |
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| 12 | If a person on the earth sees a quarter moon, that person must be within the penumbra of its shadow. |
| A) | True |
| B) | False |
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| 13 | If the distance between a surface and a source of light is increased by a factor of 3, the illumination will be one-ninth of its original value. |
| A) | True |
| B) | False |
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| 14 | A point source of light will produce only an umbra shadow. |
| A) | True |
| B) | False |
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| 15 | Since one candela is equal to one lumen per steradian, the units of intensity and illumination are the same. |
| A) | True |
| B) | False |
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| 16 | The luminous intensity is not dependent on the angle a surface makes with incident flux from a source of light. |
| A) | True |
| B) | False |
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| 17 | An isotropic source of 1 cd emits a luminous flux of 4πlm. |
| A) | True |
| B) | False |
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| 18 | The units of flux and luminous intensity have the same physical dimensions, even though they do not represent the same physical quantity. |
| A) | True |
| B) | False |
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| 19 | A lumen is the luminous flux falling on 1 m2, all points of which are located 1 m from a uniform source of 1 cd. |
| A) | True |
| B) | False |
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| 20 | The luminous intensity does not change as a surface is moved farther and farther from a light source. |
| A) | True |
| B) | False |
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| 21 | Which of the following is not an electromagnetic phenomenon? |
| A) | Heat rays |
| B) | Sound waves |
| C) | Radio waves |
| D) | Light |
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| 22 | Which of the following best applies for yellow light? |
| A) | 640 nm |
| B) | 0.4 nm |
| C) | 5 x 1014 Hz |
| D) | 580 Å |
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| 23 | The man most responsible for explaining the photoelectric effect was |
| A) | Einstein |
| B) | Planck |
| C) | Huygens |
| D) | Maxwell |
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| 24 | The wavelength corresponding to light with a frequency of 4 x 1014 Hz is |
| A) | 1.33 m |
| B) | 0.075 μm |
| C) | 7500 nm |
| D) | 750 nm |
|
| 25 | A radio frequency of 780 kHz has a wavelength of approximately |
| A) | 38 μm |
| B) | 385 m |
| C) | 0.0026 m |
| D) | 26 nm |
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| 26 | The theory that light is emitted in discrete amounts of energy rather than in a continuous fashion is known as |
| A) | the photoelectric effect |
| B) | the quantum theory |
| C) | Huygens's principle |
| D) | the electromagnetic theory |
|
| 27 | The moon is located approximately 240,000 mi from the earth. A radio signal will reach the earth from the moon in |
| A) | 1.3 min |
| B) | 0.775 s |
| C) | 1.29 s |
| D) | 0.7 min |
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| 28 | If Planck's constant is h = 6.626 x 10-34 J . s, what energy is associated with
light with a wavelength of 160 nm? |
| A) | 1.24 x 10-18 J |
| B) | 1.88 x 1015 J |
| C) | 1.24 x 10-15 J |
| D) | 1.88 x 10-15 J |
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| 29 | Which of the following scientists measured the speed of light by using an eightsided rotating mirror? |
| A) | Fizeau |
| B) | Roemer |
| C) | Galileo |
| D) | Michelson |
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| 30 | Which of the following terms best describes the nature of light from the modern point of view? |
| A) | Photons |
| B) | Waves |
| C) | Particles |
| D) | Rays |
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| 31 | Which of the following light sources of equal radiant power appears brightest? |
| A) | Red light |
| B) | Green light |
| C) | Blue light |
| D) | All are the same |
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| 32 | During a solar eclipse, a person on earth with his or her eyes protected observes that part of the sun is darkened but never all of it. This person lies in the |
| A) | umbra |
| B) | penumbra |
| C) | both (a) and (b) |
| D) | neither (a) nor (b) |
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| 33 | What is the luminous flux emitted by a 30-cd isotropic source of light? |
| A) | 30 lm |
| B) | 4 lm |
| C) | 2.4 lm |
| D) | 120πlm |
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| 34 | A 200-cd lamp is 4 m directly above a surface. The illumination is approximately |
| A) | 12.5 lm/m2 |
| B) | 25 lm/m2 |
| C) | 50 lm/m2 |
| D) | 80 lm/m2 |
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| 35 | What angle should a surface make with the incident flux if the illumination of a surface is to be reduced by a factor of one-half? |
| A) | 30° |
| B) | 45° |
| C) | 60° |
| D) | 90° |
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| 36 | A point source of light is placed 20 cm from a pencil 8 cm high. The length of the shadow on a wall 1 m from the source is |
| A) | 20 cm |
| B) | 30 cm |
| C) | 40 cm |
| D) | 50 cm |
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| 37 | The solid angle subtended at the center of a 10-cm-diameter sphere by an area of 2 cm on its surface is approximately |
| A) | 0.4 sr |
| B) | 0.04 sr |
| C) | 0.8 sr |
| D) | 0.08 sr |
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| 38 | Luminous flux is associated most closely with |
| A) | the source |
| B) | the surface |
| C) | the space between the source and the surface |
| D) | none of these |
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| 39 | A movie screen is 10 m from a light source in a projector. The screen makes an angle of 37° with the incident flux. What luminous intensity is required to give an illumination of 6 lx? |
| A) | 75.1 cd |
| B) | 751 cd |
| C) | 890 cd |
| D) | 997 cd |
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| 40 | A 200-cd light provides an illumination of 50 lx at a distance of |
| A) | 1 m |
| B) | 2 m |
| C) | 3 m |
| D) | 4 m |
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| 41 | Every point on an advancing wavefront can be considered as a source of secondary . This is known as . |
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| 42 | The is a unit of wavelength that is equal to one tenthousandth of a micrometer. |
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| 43 | Electromagnetic radiation of immediately higher energy than light is called radiation. |
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| 44 | The conversion factor relating light frequency to light energy is known as . |
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| 45 | The common unit for expressing wavelengths of electromagnetic radiation is . |
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| 46 | The process by which light is emitted when electrons strike a metallic surface is known as the . |
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| 47 | The colors corresponding to the given wavelengths are (450 nm), (480 nm), (520 nm), (580 nm), (600 nm), and (640 nm). |
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| 48 | The spectrum of electromagnetic waves is divided into the following eight major regions in order of increasing energy:
(a) (b) (c) (d) (e) (f) (g) (h) |
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| 49 | Light energy is divided equally between and fields, which are mutually perpendicular. |
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| 50 | One is equivalent to 1/680 W of yellow-green light of wavelength . |
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| 51 | The inner portion of a shadow that receives no light from the source is called the . The other region is known as the . |
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| 52 | The luminous flux per unit solid angle is known as the and is measured in . |
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| 53 | Illumination E may be calculated from the ratio of to or from the ratio of to the square of the between the source and the surface. |
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| 54 | A grease-spot photometer is used to measure by comparison with a standard source. |
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| 55 | A is the solid angle subtended at the center of a sphere by an area on its surface that is equal to the square of its . |
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| 56 | The of a surface is proportional to the luminous intensity of the light source and is inversely proportional to the square of the distance. This is sometimes called the law. |
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| 57 | When a surface makes an angle with the incident flux, the is proportional to the component of the surface to the flux. |
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| 58 | A(n) source is one that emits light uniformly in all directions. |
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| 59 | The is that part of the total radiant power emitted from a light source that is capable of affecting the sense of sight. |