Description : Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 cm and 1.7 mm B. 5 mm and 2.5 mm C. 5 cm and 2.5 cm D. 1.35 mm and 1.7 μm
Last Answer : B. 5 mm and 2.5 mm
Description : Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule? A. 1.35 cm and 1.7 mm B. 1.5 mm and 5 mm C. 1.35 dm and 1.7 cm D. 1.5 cm and 5mm
Last Answer : A. 1.35 cm and 1.7 mm
Description : Which of the following wavelengths where absorption of electromagnetic waves becomes peak due to vibrational resonances in the water vapor molecule? A. 1.35 cm and 1.7 mm B. 1.5 mm and 5mm C. 1.35 dm and 1.7cm D. 1.5 cm and 5 mm
Description : What are the electromagnetic radiations of wavelengths less than 300 angstroms? A. X-rays B. Ultraviolet rays C. Infrared D. Microwaves
Last Answer : A. X-rays
Description : The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μm is (A) 6.35 kWh/ton (B) 9.0 kWh/ton (C) 18 kWh/ton (D) 25.4 kWh/ton
Last Answer : (C) 18 kWh/ton
Description : (3) checking the penetration of ultra-violet rays to the earth Explanation: Ozone in the ozone layer filters out sunlight wavelengths from about 200 nm UV rays to 315 nm, with ozone peak absorption at about 250 nm. This ... the lower UV-C (200 nm-280 nm) and the entire UV-B band (280 nm-315 nm).
Last Answer : The advantage of detergents over soaps is – (1) Detergents are soluble in water (2) Detergents could not give much lather (3) Detergents give lather even with hard water (4) Soaps give lather with only soft water
Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s
Last Answer : (B) 16 mm/s
Description : At what particular wavelength is solar flux measured? A. 10.7 mm band B. 10.7 m band C. 10.7 cm band D. 10.7 nm band
Last Answer : C. 10.7 cm band
Description : Particles having diameter greater than 75 μm (micrometer = 10 -6 mm) are called (A) Grit (B) Dust (C) Powder (D) Smoke
Last Answer : (A) Grit
Description : A device that converts high frequency current into electromagnetic wave. A. Antenna B. Loudspeaker C. Microphone D. Transducer
Last Answer : A. Antenna
Description : What device in a waveguide system used for stopping or diverting electromagnetic wave as desired? A. Mechanical switch B. Electric switch C. Push-button switch D. Waveguide switch
Last Answer : D. Waveguide switch
Description : ____ is defined as any radiation of energy by means of electromagnetic wave. A. Emission B. Radiation C. Radio D. Broadcasting
Last Answer : A. Emission
Description : What is meant by referring to electromagnetic waves as having circular polarization? A. The electric field is bent into a circular shape. B. The electric field rotates C. The electromagnetic wave continues to circle the earth D. The electromagnetic wave has been generated by a quad antenna
Last Answer : B. The electric field rotates
Description : What are electromagnetic waves? A. Alternating currents in the core of an electromagnet B. A wave consisting of two electric fields at right angles to each other C. A wave consisting of an electric field ... to each other D. A wave consisting of two magnetic fields at right angles to each other
Last Answer : C. A wave consisting of an electric field and a magnetic field at right angles to each other
Description : Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave? A. AF amplifier B. Antenna C. Detector D. Crystal
Last Answer : B. Antenna
Description : What are electromagnetic waves? A. A wave consisting of two magnetic fields at right angles to each other B. A wave consisting of an electric field and a magnetic field at right angles to each ... core of an electromagnet D. A wave consisting of two electric fields at right angles to each other
Last Answer : B. A wave consisting of an electric field and a magnetic field at right angles to each other.
Description : An electromagnetic wave is ________ polarized when the electric field lies wholly in one plane containing the direction of propagation. A. Horizontally B. Linearly C. Circularly D. Vertically
Last Answer : B. Linearly
Description : When electromagnetic wave are propagated through a waveguide, they A. are reflected from the walls but do not travel along them B. travel along all four walls of the waveguide C. travel along the broader walls of the guide D. travel through the dielectric without touching the walls
Last Answer : A. are reflected from the walls but do not travel along them
Description : Electromagnetic wave travel at __________ in free space. A. 300,000 km/sec B. 100,000 km/ sec C. 400,000 km/sec D. 200km/sec
Last Answer : A. 300,000 km/sec
Description : An electromagnetic wave consists of A. a magnetic field only B. both electric and magnetic fields C. an electric field only D. non-magnetic field only
Last Answer : B. both electric and magnetic fields
Description : The reverberation time of a 184.2 cubic meters broadcast studio is 0.84 sec. Find the absorption effect of the materials used in metric sabines. A. 35.3 B. 10.96 C. 379.8 D. 109.6
Last Answer : A. 35.3
Description : What device measures the angle between two radio frequencies and also the direction of propagation of a wave? A. Densimeter B. Absorption wavemeter C. Goniometer D. Ergometer
Last Answer : C. Goniometer
Description : Extrinsic (OH) absorption peaks define three regions or windows of preferred operation. List the three windows of operation.
Last Answer : The first, second, and third windows of operation are 850 nm, 1300 nm, and 1550 nm, respectively.
Description : Determine the standing wave ratio of a 300-Ω line whose load is 400+j150 Ω. A. 3.55 B. 1.67 C. 5.53 D. 3.35
Last Answer : B. 1.67
Description : Is the width of the range of wavelengths emitted by the light source a. Bandwidth b. Chromatic Dispersion c. Spectral width d. Beamwidth
Last Answer : c. Spectral width
Description : The band of light wavelengths that are too long to be seen by the human eye a. Amber b. Visible c. Infrared d. Ultraviolet
Last Answer : c. Infrared
Description : _____ is an antenna made up of a number of full wavelengths A. Elementary doublet B. Log-periodic C. Long wire D. Whip
Last Answer : C. Long wire
Description : Two or more antennas separated by 9 wavelengths are used. A. Hybrid diversity B. Space diversity C. Polarized diversity D. Frequency diversity
Last Answer : B. Space diversity
Description : What is the typical separation between the two conductors in a parallel wire line? A. 0.001 to 0.01 m B. 200 to 500 mm C. 0.635 to 15.24 cm D. 2.5 to 5 in.
Last Answer : C. 0.635 to 15.24 cm
Description : Thermal radiation is an electromagnetic radiation with wavelengths in _____ range. A. 1 to 100 µm B. 0.1 to 100 µm C. 0.1 to 10 µm D. 10 to 100 µm
Last Answer : 0.1 to 100 µm
Description : In organic molecules, fluorescence seldom results from absorption of UV radiation of wavelengths lower than (A) 350 nm (B) 200 nm (C) 300 nm (D) 250 nm
Last Answer : (A) 350 nm
Description : Silica (pure glass) fibers are used because of their low intrinsic material absorption at the wavelengths of operation. This wavelength of operation is between two intrinsic absorption regions. What are these two regions called? What are the wavelengths of operation for these two regions?
Last Answer : Ultraviolet absorption region (below 400 nm) and infrared absorption region (above 2000 nm).
Description : What is the frequency of a 2-cm sound wave in sea water at 25˚C? A. 76 kHz B. 76 Hz C. 76 MHz D. 76 mHz
Last Answer : A. 76 kHz
Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8
Last Answer : (C) 0.7
Description : Calculate the reverberation time of a living room 8 ft high, 13 ft wide and 20 ft long. The total absorption of the building structure inside the room is 180.7 sabines with four persons present in the room. A. 0.5 ms B. 0.05 s C. 0.5 s D. 5 ms
Last Answer : C. 0.5 s
Description : Is 35.5 mm greater than 10 cm?
Last Answer : 10 cm is greater than 35.5 mm. (35.5 mm = 3.55 cm)
Description : Which of the following ranges identifies the amount of pressure within the endotracheal tube cuff that is believed to prevent both injury and aspiration? a) 20-25 mm Hg water pressure. Usually the ... pressure A measure of 0-5 mm Hg water pressure would indicate that the cuff is underinflated.
Last Answer : a) 20-25 mm Hg water pressure. Usually the pressure is maintained at less than 25 cm water pressure to prevent injury and at more than 20 cm water pressure to prevent aspiration.
Description : Determine the additional absorption (sabines) contributed by 10 persons in a room A. 47 B. 4.7 C. 0.47 D. 470
Last Answer : A. 47
Description : An instrument has two strings. Both have the same length and are uniform. One of the strings is under twice as much tension as the other and also twice the mass of the other. Then which of ... d) Both strings vibrate with the same frequency and have the same wave-length and the same wave velocity.
Last Answer : Ans:(d)
Description : You are measuring noise in a voice channel at 7 dB test point level. The meter reads -56 dBm (FIA weighted). What is the reading in dBrnc? A. 20 B. 32 C. 35 D. 25
Last Answer : C. 35
Description : A dielectric waveguide for the propagation of electromagnetic energy at light frequencies a. Stripline b. Microstrip c. Laser beam d. Fiber optics
Last Answer : d. Fiber optics
Description : Any energy which radiates in the form of radio waves, infrared waves, light waves, x-rays, etc. A. Radiant energy B. Electromagnetic C. Heat D. Ultraviolet
Last Answer : B. Electromagnetic
Description : A matched termination in which the electromagnetic energy is absorbed by water. A. Maximum power transfer B. Load C. Load water D. Basin
Last Answer : C. Load water
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth. B. The magnetic field is parallel to the earth. C. Both the electric and magnetic fields are horizontal D. Both the electric and magnetic fields are vertical
Last Answer : A. The electric field is parallel to the earth.
Description : What is the relationship in degrees of the electrostatic and electromagnetic fields of an antenna? A. 0 degree B. 45 degrees C. 90 degrees D. 180 degrees
Last Answer : C. 90 degrees
Description : What is caused by the transverse nature of electromagnetic waves? A. Polarization B. Interference C. Beamwidth D. Gain
Last Answer : A. Polarization
Description : The electromagnetic radiation theory was profounded by A. Sir Edward Appleton B. Guglielmo Marconi C. Heinrich Hertz D. James C. Maxwell
Last Answer : D. James C. Maxwell
Description : Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz, propagated in space without artificial guide. A. Space waves B. Terrestrial waves C. Mobile D. Hertzian waves
Last Answer : D. Hertzian waves
Description : What kind of receiver is used in conventional telephone handset? A. Capacitor B. Electromagnetic C. Carbon D. Ceramic