Acoustics1. a. b. c. d. Which best describe the sound wave? It may be longitudinal It is always transverse It is always longitudinal All of the above 2. Which of the following can not travel through a vacuum? a. Electromagnetic wave b. Radio wave c. Soundwave d. Light wave 3. Through which medium does sound travel fastest? a. Air b. Water c. Steel d. Mercury 4. a. b. c. d. Speed that is faster than that of sound. Ultrasonic Supersonic Subsonic Transonic 5. a. b. c. d. What is the speed of sound in air at 20°C? 1087 ft/s 1100 ft/s 1126 ft/s 200 ft/s 6. Calculate a half wavelength sound for sound of 16000 Hz a. 35 ft b. 10 ft c. 0.035 ft d. 100 ft 7. The lowest frequency that a human ear can hear is a. 5 Hz b. 20 Hz c. 30 Hz d. 20 Hz 13. When waves bend away from straight lines of travel, it is called a. Reflection b. Diffraction c. Rarefaction d. Refraction 8. Sound that vibrates at frequency too high for the human ear to hear (over 20 kHz) a. Subsonic b. Ultrasonic c. Transonic d. Stereo 14. The amplitude of sound waves, the maximum displacement of each air particle, is the property which perceive as _____ of a sound a. Pitch b. Intensity c. Loudness d. Harmonics 9. The frequency interval between two sounds whose frequency ratio is 10 a. Octave b. Half octave c. Third-octave d. Decade 10. A 16 KHz sound is how many octaves higher than a 500 Hz sound a. 2 b. 5 c. 4 d. 8 11. is a/an a. b. c. d. Sound waves composed of but one frequency Infra sound Pure tone Structure borne Residual sound 12. Sound wave has two main characteristics which are a. Highness and loudness b. Tone and loudness c. Pitch and loudness d. Rarefactions and compressions 15. It is the weakest sound that average human hearing can detect. a. SPL = 0 dB b. Threshold of hearing c. Reference pressure = 2 x 10-5N/m2 d. A, b, c 16. What is a device that is used to measure the hearing sensitivity of a person? a. Audiometer b. OTDR c. SLM d. Spectrum analyzer 17. What is the device used in measuring sound pressure levels incorporating a microphone, amplification, filtering and a display. a. Audiometer b. OTDR c. SLM d. Spectrum analyzer 18. What weighted scale in a sound level meter gives a reading that is most closely to the response of the human ear? a. Weighted scale A b. Weighted scale B c. The sound pressure level is increased by _____ dB if the intensity is doubled. dB a. a.007 W/m2. a. Reverberation 24. If four identical sounds are added what is the increase in level in dB? a. Refraction d. Weighted scale C d. Baffle d. 4 c. a. floors or ceilings. Watts 28. a. Required time for any sound to decay to 60 Echo time Reverberation time Delay time Transient time 32. 6 21. Calculate the reverberation time of the room. 200 dB b. 5 d. 140 dB 30. 20 dB c. 91 dB c. 108 W/m2 d. It is the device used to calibrate an SLM? Microphone Pistonphone Telephone Filter d.5 sec c. The transmission of sound from one room to an adjacent room. therefore simulating free field conditions. For aircraft noise measurements. Sound concentration c. Pascal d. Calculate the sound intensity level in dB of a sound whose intensity is 0. a. Sound pressure level 27. A room containing relatively little sound absorption a. Amplifier c. 88 W/m2 26. Sound shadow Reverberation 31. d. Flutter echo b. 3 b. It is an audio transducer that converts acoustic pressure in air into its equivalent electrical impulses a. 3 b. d. Live room d. 98 dB d. Free-field 33. 0. Loudspeaker b. Sound intensity d. The sound pressure level is increased by _____ dB if the pressure is doubled. a. a. 4 c. Weighted scale A b. Sound energy c. b. What is the sound intensity for an RMS pressure of 200 Pascal? a. 90 W/m2 b. Reflection c. Weighted scale C Weighted scale D 19. b. Decibel c. the weighting scale that is used is _____. 101 dB 29. Live room d. Dead room b. A room in which the walls offer essentially 100% absorption. d. via common walls. 98 W/m2 c. Dead room b. 4 c. Closed room 34. A measure of the intensity of sound in comparison to another sound intensity a. a. Sound pressure b. 95 dB b. which has a volume of 8700 ft3 and total sound absorption 140 sabins. d. 14 dB 25. 6 22. 0. Phon b.3 sec b. 5 d.53 sec 35. c. Weighted scale B c. What is the sound pressure level for a given sound whose RMS pressure is 200/m2? a. Anechoic room c. c. 3. _____ is the continuing presence of an audible sound after the sound source has stop. a. Anechoic room c. a. 6 23. Weighted scale D 20. 3 b. Flanking transmission b. 3 sec d. Microphone . 5 d. _____ is the sound power measured over the area upon which is received. An amplifier can deliver 100 W to a loudspeaker. -40 dB 43. -10 dB b. c. Low impedance c. d. a. A microphone that uses the piezoelectric Dynamic Condenser Crystal Carbon 39. 30 dB d. b. A circuit that divides the frequency components into separate bands in order to have individual feeds to the different drivers. Distortion c. Frequency response 41. d. d. Converts electrical energy to mechanical energy d. a. Using a microphone at less than the recommended working distance will create a _____ which greatly increases the low frequency signals. 10 46. c. Converts sound waves into current and voltage b. a. a. Mid-range d. d. Converts current variations into sound waves c. Proximity effect c. Carbon 37. Drop out d. High impedance b. _____ is a type of loudspeaker driver with an effective diameter of 5 inches used at midrange audio frequency. What is the maximum intensity 300 ft from it? a. effect a. Microphone b. a. Panel board 49. Sensitivity b. a. If the rated efficiency of the loudspeaker is -60 dB. Speaker is a device that a. Magnetic 38. Magnetic assemble d. c. 20 dB c. a. b. b. movie. 8 d. Dynamic d. All of the above 42. -30 dB d. Suspension system b. _____ is early reflection of sound. It is an enclosure used to prevent front and back wave cancellation. _____ is measure of how much sound is produced from the electrical signal. Loudspeaker b. Woofer c. c. The impedance of most drivers is about _____ ohms at their resonant frequency. It is a transducer used to convert electrical energy to mechanical energy. Roll-off b. Driver c. a. _____ is a pressure type microphone with permanent coil as a transducing element. Magnetic d. What is the unit of loudness? Sone Phon Decibel Mel . Dividing network c. A microphone which has an internal impedance of 25 kΩ is _____ type. It describes the output of a microphone over a range of frequencies. Baffle c. Magnet assembly d. Driver 47. A or C 40. Noise reduction system used for film sound in Dolby DBx dBa dBk 51.36. Converts electrical energy to electromagnetic energy 45. What is its rated efficiency? a. Directivity b. a. 4 b. Dynamic b. -20 dB c. 10 dB b. Condenser c. A loudspeaker radiates an acoustic power of 1 mW if the electrical input is 10 W. a. a. a. Tweeter b. Sensitivity c. None of the choices 52. Efficiency d. 40 dB 44. Frame 48. 6 c. Frequency response d. a. b. Echo Pure sound Reverberation Intelligible sound 50. Baffle d. 36 kHz d. The center to center spacing between two adjacent stations in the Phil. Noy b. What is the spacing between any two adjacent channels in the FM broadcast band? a. d. d. c. Horizontal c. Auxiliary Tx b. c. One of the main considerations in the selection of antenna site is (AM) a. 7 d. One of the broadcast transmission auxiliary services is: a. c. b. 5 b. b. 15 d. Quarternary Service Area 60. Navigation b. What does the acronym STL stand for? Station-to-link Signal-to-loss-ratio Shout-to-live Studio-to-transmitter-link 67. 14 65. Coordination and Control d. Remote pick-up b. Telephony c. 100 phons b. Intermittent Service Area d. Artificial Antenna 61. The service area where the signal is not subject to fading and co-channel interference. a. Secondary Service Area c. a. Elliptical 58. a. Elevation of the site d. 10 Hz d. d. Bed time Experimental period 59. a. What is the loudness level of a 1KHz tone if its intensity is 1 x 10-5W/cm2? a. 200 kHz c. band? a. A unit of noisiness related to the perceived noise level a. How many AM stations can be accommodated in a 150-kHz bandwidth if the highest modulating frequency is 10 kHz? a. 110 phons d. What are the frequency limits of the MF BC 300-3000 kHz 3-30 MHz 535-1605 kHz 88-108 MHz 63. Broadcasting d. It is a resistive load used in place of an antenna to test a transmitter under normal loaded condition without actually radiating the transmitter’s output signal. 105 phons c. 200 KHz d. speech. Conductivity of the soil b. 20 KHz 57. Accessibility 68. STL c. 20 KHz b. Primary Service Area b. Short wave broadcasting operates in what MF HF VHF VLF 66. Circular d. Nighttime c. Zero b. Height of the terrain c. 10 b. 9 kHz b. 20 62. music or image intended for reception by the general public? a. All of the above 69. Communication. The part of a broadcast day from 6 PM to 6 AM local time a. Phon 54. The operating power of the auxiliary transmitter shall not be less than _____% or never greater than the authorized operating power of the main transmitter. What is the process of sending voice. 20 Hz c.53. What is the frequency tolerance for the RF carrier in the standard AM radio broadcast band? a. a. Sone d. Vertical b. a. band? a. 800 kHz 64. Main Tx c. Daytime b. Mixing 56. b. Secondary Tx d. The transmitting antenna for an AM broadcast station should have a _____ polarization. 10 c. d. dB c. 100 phons Broadcasting 55. 800 KHz . 15 c. AM BC band is ____. 36 KHz c. The normal frequency for an SCA subcarrier is _____ KHz. DSB 79.3 MHz d. Neither a or b 81. a. 19 73. Class C b. does a monaural receiver produce all the sounds that a stereo does? a. What is the radio transmission of two separate signals. 2 kHz c. 19 kHz d. 67 KHz 74. When fed to the stereo FM modulator. ISB d. in what form are the L – R signals? a. Either a or b d. How are guardbands allocated in commercial FM stations? a. 38 d. What is the modulation used by the stereophonic subcarrier? a. FM b. 15 kHz modulation . After the matrix at the TX d. 75 kHz deviation d. The first channel in the FM BC band has a center frequency of a. After the matrix at the TX d. 76 c. 80. Class B 83. Class D b. An FM broadcast station. A class of FM station which is limited in antenna height of 500 ft. 50 kHz on each side of the carrier c. 88. Before the matrix at the RX c. Class C c. Before the matrix at the TX b. Before the matrix at the RX c. The carrier frequency tolerance for FM broadcasting is _____. and right.25 MHz 10 kHz 19 KHz 38 KHz 75. which has an authorized radiated power not exceeding 125 KW: a. c. The class of FM station. A&C 86. A monaural FM receiver receives only the _____ signal of a stereo multiplex transmission. Class D d. above average terrain a. Before the matrix at the TX b. AM c. No c. Class B 85. 20 kHz d. d. TV d. 30 kHz 78. EBS c. Pilot transmission d.1 MHz c. Stereo system c. L–R c. Monophonic transmission 76. Where is the pre-emphasis added in a stereo FM system? a. An additional channel of multiplex information that is authorized by the FCC for stereo FM radio stations to feed services such as commercial-free programming to selected customers. Yes b. 88. a. STL b. left. 108 MHz 71. used to create a multidimensional effect on the receiver? a. Class A d. After the matrix at the RX 72. L+R b. With stereo FM transmission. SCA b.70. b. Both a & b d. 88 MHz b. d. EIA SCA 82. Where is de-emphasis added in a stereo FM system? a. PM c. 67 b. What type of broadcast service might have their antennas on top of hills? a. 38 kHz What is the pilot signal for stereo FM? 4. Class D b. After the matrix at the RX 77. Class A c. DSBSC c. Class B 84. a. Class A d. a. AF b. which has an authorized transmitter power not exceeding 10 KW and ERP not exceeding 30 KW: a. a. FM b. 25 kHz on either sides of the transmitting signal b. Class C c. 25 kHz b. 2 kHz b. 498 MHz 500 MHz 101. AM 90. b. b. 600 89. 22% blue d. Estimate the bandwidth occupied by the sound portion of a TV transmission in US.25 MHz 55. 41. To minimize interference between signals at received end 92. Eliminate attenuation of both video and audio c. 41. FM c. Noise b. 10 b. Excessive BW c. low band UHF 102. a. Low band UHF c.5 MHz c. 11% blue b. 10 Hz d. What is the frequency tolerance in the color carrier of TV broadcasting? a. 22% blue 104. b. C3F d. what is the frequency of the tuner’s local oscillator. 103. If the sound carrier for UHF channel 23 is 529. c.75 MHz.25 MHz 55.75 MHz 96. Better efficiency b. 11 and 13 are known as _____.26 MHz c 174 MHz d 175.25 MHz.83 MHz 211.75 MHz 59.75 MHz 59. 5. How many commercial FM broadcast channels can fit into the bandwidth occupied by a commercial TV station? a.25 MHz b 175. 20% green. 33% red. when turned to this channel? a. What is color subcarrier for channel 2? 68. Green . 41. c. 0. 4.87. Flicker a. 99. What is the main reason why television picture signal uses amplitude modulation. b. d. The picture and sound carrier frequencies in a TV receiver are _____ respectively. What is eliminated by using interlaced scanning? a.75 MHz 41.75 MHz 97.25 MHz 95. What is the separation between the lower limit of a channel and the aural carrier? a.25 MHz 58. What percentage of the primary colors used in color TV are needed to produce the brightest white? a. d. Yellow c. What is the aural carrier for channel 3? 61.83 MHz 98. b. 50% red. d.25 MHz 65. 25 kHz b. 30 d. 200 c. a. 1. 800 kHz c.25 MHz 100. 125 d. 30% red.75 MHz.25 MHz 45.25 MHz 65.25 MHz b. a. 33% green. How many international commercial AM broadcast channels can fit into the bandwidth occupied by a commercial TV station? a. 45. a. 45.83 MHz 214. Frame d. c.25 MHz b. What is the exact picture carrier frequency for frequency for channel 7 offset by – 10 KHz? a 175. 1 kHz 93. a. Mid band UHF b. 20 c. What is the separation between visual and aural carrier in TV broadcasting? a. High band VHF d. 28% green.25 MHz. c. b. What is the visual carrier for channel 12? 205. TV channels 7. 80 kHz d. 58% red. 511 MHz c. 33% blue c. The color with the most luminance is a.5 MHz c.24 MHz 94.75 MHz. d. 1. 0. 4. 59% green. Maintain synchronized scanning between transmit and received video d.25 MHz c. while voice is frequency modulated? a. a. PM b.75 MHz d. Red b. c. What kind of modulation is used for the sound portion of a commercial broadcast TV transmission? a. 40 88.75 MHz d. d. 571 MHz b. 5. 100 b.75 MHz 45. 20 Hz c. 200 kHz 91. a. 4 106. d. Z 112. Blue d. Y signal d. Monochrome . a. Y signal d. B and C c. 0.58 MHz c. I signal b. The three complementary colors are: White. Which of the following is not a requirement for a color TV signal? a. Carrier d. Q signal c. Contrast control 115. What is the aspect ratio for HDTV system? 4/3 9/7 19/6 16/9 120. cyan Black. magenta. The _____ affects the difference between black and white on the picture tube and controls the gain of the video amplifier a. 1. Z signal 114. Hue b. A and D 110. In the previous problem.304 c. G=0.254 c. a. C and D d. b. 0. fushcia 108. 0. A and B b. How many electron beams actually leave the electron gun of a single-gun color CRT? a.d. Blue 105. The signal that will give the exact color wavelength is _____. c. Which of the following represents the intensity of a given color? a. The studio camera produces a luminance signal that contains information about a. b. Monochrome 121. Hue b. Volume control c.3 MHz? a. X signal 113. What is the difference between the sound carrier and color subcarrier frequencies? a.498 b. 0. 0. 1. Red b.2. calculate the chrominance signal a. b) violet. a. 1/3 117. Simulate a wide variety of colors d. Which of the following consist of two of the three primary colors in television signal? a) red.5 MHz? a. 0. Within 6 MHz bandwidth c. 0. Brightness variations of the picture information are in which signal? a.5 MHz d. white. b. where 1 represents the maximum signal possible. The speech content The brightness of the scene The color content of the scene 111. I b. a. gray Yellow. d. 0. Y d. Green 109. Power control d. and d) blue a. c. Which of the following is the color video signal transmitted as amplitude modulation of the 3.25 MHz b. 4. compatibility with b lack and white receivers b. What does aspect ratio mean? Ratio of the screen width to its height Ratio of the screen height to its width Ratio of the screen diagonal to its width Ratio of the screen diagonal to its height 119. c) yellow. yellow.58 MHz C signal in quadrature with bandwidth of 0 to 0. Suppose the signal from a color camera has R=0. 3 d.58 MHz C signal with bandwidth of 0 to 1. c.8. Functional with baron super antenna 116. The musical content b. indigo. White c. Determine the value at the luminance signal a.498 d. Brightness control b. Saturation c. Q signal c. d. Carrier d. c. 2 c.022 107. cyan Violet.1325 d. I signal b. When the colors Magenta and Yellow are mixed the resultant color is: a. Which of the following is the color video signal transmitted as amplitude modulation of the 3.4 and B=0. Saturation c.305 b. d. 1 b.92 MHz 118. 3. Q c. 15750 Hz d. The _____ ensures that the electron beam will strike the correct phosphor dot on the TV screen. 2500 138.S. The serrations d.2 MHz b. Number of pixels d. 30 Hz b. 157625 Hz 129. Sneaking d.5 c. 30 Hz b. What scheme is employed to cause the electron beam in the TV receiver and the electron beam in the studio camera to track identically? a. Equalizing pulses in TV are sent during a. Vidicon d. 15750 134. Diplexer d. c. How many horizontal lines are used to develop a TV raster? a. Fitting c. Utilization d. Coating b. Equalizing intervals 127. video? a. 157625 Hz 136. Resolution What is the North American TV standard PAL SECAM NTSC FCC 131. Interleaving .122. what is the relationship between the amplitude of the signal and the intensity of the electron beam in the receiver picture tube? a. a. 312. The channel width in the U. Duplexer 128. 615 b. The greater the amplitude the lighter the picture d. NTSC c. 750 d. No effect 124. 123. 50 kHz c. TV system is : 2 MHz 6 MHz 7 MHz 8 MHz 137.5 MHz 132. What is the highest video frequency set by the FCC for commercial TV? a. d. 75 kHz d. In a TV receiver. 525 c. 6 MHz d. 60 Hz c. 15 MHz c. d. Vertical blanking c. If there are 625 lines per TV picture then the number of lines per field are: a. Number of frames per second b. In a composite video signal. What is the return of the electron beam in a CRT from right to left or from bottom to top? a. The lower the amplitude the darker the picture c. b. What is the maximum allowable frequency deviation in the audio section of a TV signal for PAL/SECAM? a. 157625 Hz 125. What is the process of placing the chrominance signal in the band space between portions of the luminance signal? a. 1250 b. Interlacing b. Interlacing b. Horizontal blanking b. What determines the maximum number of vertical picture elements? a. what is the horizontal signal frequency? a. In a TV receiver. Image orthicon b. 25 kHz b. Flyback c. What is the frame frequency in the US TV system? a. 60 Hz c. Number of lines on the screen c. a. Aperture Mask c. 30 Hz b. 100 kHz 135. 5. The greater the amplitude the darker the picture b. Relay b. 625 d. what is the vertical signal frequency? a. Plumbicon 130. Iconoscope c. Transmission of sync pulses 126. 15750 Hz d. 4. Interleaving d. 15750 Hz d. b. Number of fields per second 133. c. 60 Hz c. It is the popular TV camera designed with much smaller package and lower cost than its earlier designs a. RF amplifier b. Silicon Vidicon 21C 22B 23C 24C 25B 142. Bits 144. IF amplifier d. 60 Hz for vertical sync and scanning c. A1 d. Audio amplifier c. Utilization ratio c. 63. arsenic and tellurium a. 16. 15. Pixel d. Tuned circuit 140. What section of a TV receiver determines the bandwidth and produces the most signal gain? a.5 μs c. Blip b. c.500 Hz for the vertical scanning frequency Answers: 1C 2C 3C 4B 5A 141. Saticon d. d. 10.2 μs b. Vidicon c.139. 31.67 μs d.500 Hz for the equalizing pulses and serrations in the vertical sync pulse d. Monochrome 6C 7B 8B 9A 10B 11B 12C 13D 14C 15D 16A 17C 18A 19D 20B 26D 27A 28D 29A 30D 31B 32C 33B 34C 35D 36A 37A 38C 39C 40C 41C 42D 43C 44B 45C 46D 47C 48B 49A 50A 51B 52A 53A 54C 55C 56B 57A 58A 59A 60D 61B 62C 63C 64C 65B 66D 67A 68D 69C 70B 71B 72B 73D 74C 75A 76D 77A 78A 79A 80B 81D 82B 83D 84D 85D 86A 87C 88D 89B 90C 91D 92D 93B 94C 95A 96C 97C 98A 99C 100D 101C 102D 103A 104B 105A 106A 107C 108B 109B 110C 111C 112A 113B 114D 115D 116C 117D 118A 119D 120A 121B 122B 123C 124B 125D 126B 127B 128C 129B 130A 131A 132B 133B 134B 135C 136A 137B 138D 139B 140D 141C 142D 143C 144B 145C . 31. b.750 Hz for horizontal sync and scanning b. How much time elapses between the start of one horizontal sync pulse and the next? a. The camera tube that uses selenium. It is the quality of the TV picture after imperfections a. Burst c. The components of composite video signal Chroma signal Blanking pulse Synchronizing pulse All of these 143. Aspect ratio b. Plumbicon b. are: a. 100 μs 145. Which of the following frequencies is wrong? a. What is the smallest amount of information that can be displayed on a television screen? a.