Description : The agreed standard for measuring loudness is the loudness sensation produced by a 1000 Hz sine wave _____ dB above the listener’s threshold of hearing. A. 80 B. 50 C. 30 D. 40
Last Answer : D. 40
Description : For a loudness level between 110 and 120 dB, the maximum daily exposure limit is ____ minute (s). A. 1 B. 60 C. 20 D. 45
Last Answer : A. 1
Description : What loudness level in which permanent damage to hearing is possible? A. 120 dB B. 140 dB C. 130 dB D. 150 dB
Last Answer : D. 150 dB
Description : The sound intensity received from the nearby jet plane is 12.6 µW/m2 and that from another jet plane some distance away is 0.45 µW/m2 . Find the relative loudness of the two. A. 14.0 dB B. 14.5dB C. 12.5 D. 14.5
Last Answer : B. 14.5dB
Description : At what loudness level do pitch (in mels) and frequency (in Hz) are numerically equal? A. 0 dB B. 20 dB C. 60 dB D. 40 dB
Last Answer : D. 40 dB
Description : A reading of -50 dBm on the disturbing pair, and -80 on the disturbed pair equals _____ dB of crosstalk coupling. A. 20 B. 30 C. 60 D. 25
Last Answer : B. 30
Description : What is the required quality factor for an SSB filter with the following data: center frequency= 1 MHz, the desired attenuation level of the unwanted sideband= 80 dB and the separation between sidebands= 200 Hz? A. 1,250 B. 12,500 C. 125,000 D. 25,000
Last Answer : C. 125,000
Description : Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW
Last Answer : A. 0.871 μW
Description : How much louder is 80 phons over 60 phons? A. 1000 times B.4 times louder C. 100 times D. Twice as loud
Last Answer : B.4 times louder
Description : What is affected by the distance between the listener and the source of the sound because the intensity varies inversely with the square of the distance? A. Volume B. Pitch C. Loudness D. Frequency
Last Answer : C. Loudness
Description : The loudness level increased from 40 to 56 phons. What is the increase in loudness sensation? A. 3 times B. 4.5 times C. 2 times D. 4 times
Last Answer : A. 3 times
Description : What is the typical loudness level of a watch ticking? A. 0 phon B. 40 phons C. 20 phons D. 60 phons
Last Answer : C. 20 phons
Description : What is typical loudness level of an acoustic guitar 1 foot away? A. 60dB B. 100dB C. 80dB D. 40dB
Last Answer : C. 80dB
Description : If the loudness level is 100 phons, what is this in sone unit? A. 100 B. 90 C. 106 D. 96
Last Answer : C. 106
Description : The sound energy per unit area at right angles to the propagation direction per unit time. A. Sound intensity B. Loudness C. Coherence D. Sound stress
Last Answer : A. Sound intensity
Description : ____________ is the average rate of transmission of sound energy in a given direction through a cross sectional area of 1 sq.m. at right angle to the direction. A. Sound pressure B. Sound intensity C. Pressure variation D. Loudness
Last Answer : B. Sound intensity
Description : ECE Board Exam March 1996 One type of pulse communications system uses pulse that appear as a group, and which vary in number according to the loudness of the voice. This type of ... A. pulse duration modulation B. pulse amplitude modulation C. pulse code modulation D. pulse position modulation
Last Answer : A. pulse duration modulation
Description : Determine the terrain sensitivity loss for a 4-GHz carrier that is propagating over a very dry, mountainous area. A. -1.25 dB B. -3.05 dB C. -2.01 dB D. -5.01 dB
Last Answer : A. -1.25 dB
Description : Is it legal or acceptable for apartment dwelling neighbors to play the stereo at deafening levels all day long?
Last Answer : No! Complain to your landlord. If the noisy party is your landlord, MOVE!
Description : A teacher should keep his voice in the class Options: A) High Enough To Be Heard By Every Student Clearly B) Loud, So That Every One Can Hear Clearly C) Moderate D) Sometime Low And Some Time High
Last Answer : D) Sometime Low And Some Time High
Description : In acoustics, _____ is the apparent change in frequency or pitch when a sound source moves either toward or away from a listener. A. flanking B. reverberation C. Doppler effect D. echo
Last Answer : C. Doppler effect
Description : What height of an ionized layer is determined from the time interval between the transmitted signal and the ionospheric echo at vertical incidence? A. Virtual height B. Apparent height C. Actual height D. Effective height
Last Answer : A. Virtual height
Description : If a sudden loud noise in the range of 100-150 dB ruptured one's eardrum and caused bleeding from the ears how long would it take for hearing to return in a best case scenario?
Last Answer : An internet search was not definitive on whether or not the eardrums would rupture, but there is the possibility. If this is describing an actual situation, your time would be best spent talking to a doctor.
Description : Can a sudden loud noise in the range of 100-150 dB cause bleeding from the nose?
Last Answer : An internet search found one page that indicated a high-dB level might cause a nose bleed, but that would be unusual. If you are describing a current condition, your time would be better spent talking with a doctor.
Description : Cable attenuation is usually expressed in terms of a. Loss per foot b. dB/km c. intensity per mile d. voltage drop per inch
Last Answer : b. dB/km
Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB
Last Answer : C. 3.9 dB
Description : What is the gain, in dB of a helical antenna with diameter of λ/3, 10 turns at pitch of λ/4, used at 100 MHz? A. 16 B. 41.1 C. 31.4 D. 1.25
Last Answer : A. 16
Description : The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts
Last Answer : B. 158 watts
Description : What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in a southernly direction? A. 25000 dB B. 10 dB C. 100 dB D. 20 dB
Last Answer : B. 10 dB
Description : What is the theoretical gain of a Hertzian dipole? A. 1.76 dB B. 2.15 dB C. 3 dB D. 0 dB
Last Answer : A. 1.76 dB
Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24
Last Answer : B. 2.6
Description : If an antenna has a gain of 3 dB, it increases the output of the transmitter by A. 10,000 times B. 1000 times C. 100 times D. 1 million times
Last Answer : B. 1000 times
Description : What is the gain of the Hertzian dipole over isotropic antenna? A. 1.64 dB B. 2.15 dB C. 1.76 dB D. 1.55 dB
Last Answer : C. 1.76 dB
Description : What is the free space attenuation of a satellite communications system operating at 36,000 km above the earth at 5.0 GHz? A. 198 dB B. 202 dB C. 142 dB D. 138 dB
Last Answer : A. 198 dB
Description : When the elevation angle of a geostationary satellite is 23˚ and the transmitting frequency is 3840 MHz, what is the free space loss in dB? A. 196 dB B. 200 dB C. 150 dB D. 100 dB
Last Answer : A. 196 dB
Description : The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB
Last Answer : A. 403 dB
Description : What is the approximate path loss from satellite-to-earth station? A. 100 dB B. 150 dB C. 175 dB D. 200 dB
Last Answer : D. 200 dB
Description : Which noise figure represents the lowest noise in receiver? A. 1.6 dB B. 2.1 dB C. 2.7 dB D. 3.4 dB
Last Answer : A. 1.6 dB
Description : At what power level does a 1 KHz tone cause zero interference (144 weighted)? A. 90 dB B. 90 dBm C. -90 dBm D. -90 dBm
Last Answer : D. -90 dBm
Description : Your Western Electric 3A test set meter reading is -23 dBm at at test point level of -8 dB. This is ______ dBrnc0. A. 75 B. 29 C. 30 D. 31
Last Answer : A. 75
Description : You are measuring noise at a -6 dB level point, using the Lenkurt 601A, F1A weighting network, and a flat meter. The meter reading is -59 dBm. This is _________ dBa0. A. 24 B. 12 C. 23 D. 32
Last Answer : D. 32
Description : You are measuring noise at a +3 dB level point, using the Lenkurt 601A, F1A weighting network, and a flat meter. The meter reading is -57dBm. This is ________dBa0. A. 20 B. 15 C. 25 D. 17
Last Answer : C. 25
Description : Interfering effect of noise, C message weighted, is _________. A. dBa B. dBm C. dBmc D. dB
Last Answer : C. dBmc
Description : The noise figure of the first circuit in tandem connection is 10.5 dB while its power gain is 15, what is the over all noise figure if the second circuit has a noise figure of 11 dB? A. 11.59 dB B. 11.23 dB C. 10.79 dB D. 10.5 dB
Last Answer : C. 10.79 dB
Description : Three identical circuits having 10 dB signal noise-to-noise ratio each are connected in tandem with each other, what is the overall S/N? A. 5.23 dB B. 14.77dB C. 30 dB D. 40 dB
Last Answer : A. 5.23 dB
Description : What signal-to-noise ratio is required for satisfactory television reception? A. 10 dB B. 30 dB C. 40 dB D. 20 dB
Last Answer : C. 40 dB
Description : What is the quantization signal-to-noise ratio if an 8-bit PCM code is used? A. 40 dB B. 50 dB C. 60 dB D. 65 dB
Last Answer : B. 50 dB
Description : What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W
Last Answer : A. 317 W
Description : What is the insertion loss of connector type splices for a single mode optical fiber? A. 0.51 dB B. 0.49 dB C. 0.31 dB D. 0.38 db
Last Answer : D. 0.38 db
Description : What is the effective radiated power of a repeater with 120 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 601 W B. 240 W C. 60 W D. 379 W
Last Answer : C. 60 W