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1 | |
Although earlier scientists believed light was transmitted by particles, it is now established that light is a wave phenomenon. |
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| | A) | True |
| | B) | False |
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2 | |
Infrared rays are more energetic than visible or ultraviolet rays. |
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| | 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. |
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| | 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. |
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| | 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. |
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| | A) | True |
| | B) | False |
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6 | |
The nanometer is 10 times as large as the angstrom. |
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| | A) | True |
| | B) | False |
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7 | |
The energy of light is directly proportional to the wavelength. |
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| | A) | True |
| | B) | False |
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8 | |
The first successful terrestrial measurement of the speed of light was made by Fizeau. |
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| | A) | True |
| | B) | False |
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9 | |
The photoelectric effect occurs when light is emitted as a result of electron bombardment. |
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| | A) | True |
| | B) | False |
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10 | |
The nature of light is no different fundamentally from the nature of heat radiation. |
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| | 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. |
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| | 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. |
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| | 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. |
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| | A) | True |
| | B) | False |
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14 | |
A point source of light will produce only an umbra shadow. |
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| | 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. |
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| | 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. |
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| | A) | True |
| | B) | False |
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17 | |
An isotropic source of 1 cd emits a luminous flux of 4πlm. |
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| | 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. |
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| | 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. |
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| | 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. |
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| | A) | True |
| | B) | False |
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21 | |
Which of the following is not an electromagnetic phenomenon? |
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| | 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? |
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| | 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 |
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| | 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 |
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| | A) | 1.33 m |
| | B) | 0.075 μm |
| | C) | 7500 nm |
| | D) | 750 nm |
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25 | |
A radio frequency of 780 kHz has a wavelength of approximately |
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| | 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 |
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| | A) | the photoelectric effect |
| | B) | the quantum theory |
| | C) | Huygens's principle |
| | D) | the electromagnetic theory |
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27 | |
The moon is located approximately 240,000 mi from the earth. A radio signal will reach the earth from the moon in |
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| | 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? |
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| | 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? |
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| | 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? |
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| | 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? |
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| | 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 |
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| | 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? |
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| | 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 |
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| | 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? |
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| | 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 |
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| | 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 |
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| | 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 |
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| | 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? |
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| | 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 |
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| | 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. |
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