Description : Light waves are different from sound waves in that 1. Light waves are electromagnetic but sound waves are not 2. Light waves can travel through water but sound waves cannot 3. Light travels with the same speed in all media 4. Light ... /are correct? (a) 1 and 5 (b) 2 and 3 (c) 3 and 4 (d) 1 and 4
Last Answer : Ans:(a)
Description : How much time is required for electromagnetic energy to travel 1 nautical mile and return to the source?
Last Answer : 12.36 microseconds.
Description : What happens to the speed of electromagnetic energy traveling through air as the altitude increases?
Last Answer : Speed increases
Description : The Doppler effect causes a change in what aspect of rf energy that strikes a moving object?
Last Answer : Frequency.
Description : If a wave's electric lines of force rotate through 360 degrees with every cycle of rf energy, what is the polarization of this wave?
Last Answer : Circular polarization.
Description : Why is the physical length of a coaxial cable transmission line shorter than its electrical length? A. Skin effect is less pronounced in the coaxial cable B. RF energy moves slower along the ... higher in the parallel feed line D. The characteristic impedance is higher in the parallel feed line
Last Answer : B. RF energy moves slower along the coaxial cable
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 : The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called: w) ir x) ultra-violet y) rf z) gamma ray
Last Answer : ANSWER: X -- ULTRA-VIOLET
Description : What two methods are used to compensate for the problems that cause low gain in an rf amplifier?
Last Answer : . RF transformers are used and the transistor is neutralized.
Description : What problem is caused in an rf amplifier by a loosely coupled transformer?
Last Answer : A too-narrow bandpass.
Description : What is the most common form of coupling for an rf amplifier?
Last Answer : Transformer coupling.
Description : Can a parallel LC circuit be used as the frequency determining network for an rf amplifier?
Last Answer : Yes.
Description : What is the purpose of a frequency-determining network in an rf amplifier?
Last Answer : To provide maximum impedance at the desired frequency.
Description : If current gain is required from an rf amplifier, what type of component should be used as an output coupling element?
Last Answer : A step-down transformer.
Description : What is the result of pulsing a pulsed rf amplifier when no rf is present?
Last Answer : Oscillations at an undesired frequency.
Description : Rotation of an rf-feed source to produce a conical scan pattern is identified by what term?
Last Answer : Nutation.
Description : At what point on an open-circuited rf line do voltage peaks occur?
Last Answer : At 1/2 wavelength from the end and at every 1/2 wavelength along the line
Description : If the rf amplifier discussed has an 80 milliwatt input, what would be the maximum output?
Last Answer : 800 watts.
Description : What is the most common method of testing a fixed rf attenuator?
Last Answer : Rf substitution method.
Description : Normally, how are high-power rf tubes tested?
Last Answer : In their circuit.
Description : Name the three main sections of a typical rf signal generator.
Last Answer : Oscillator circuit, modulator, and output control circuit.
Description : How does the reactance-tube modulator impress intelligence onto an rf carrier?
Last Answer : By changing the reactance of an oscillator circuit in consonance with the modulating voltage.
Description : For what class of operation is the final rf power amplifier of a plate-modulator circuit biased?
Last Answer : Class C
Description : What term is used to describe a situation in which atmospheric temperature first increases with altitude and then begins to decrease?
Last Answer : Temperature inversion.
Description : What characteristic is determined by the time required for a voltage wave to travel from the input end of an artificial transmission line to the output end and back again?
Last Answer : Pulse width
Last Answer : Pulse width.
Description : What is caused by the transverse nature of electromagnetic waves? A. Polarization B. Interference C. Beamwidth D. Gain
Last Answer : A. Polarization
Description : Fiber optics posses following properties __________ a) Immune electromagnetic interference b) Very less signal attenuation c) Very hard to tap d) All of the mentioned
Last Answer : d) All of the mentioned
Description : Interference of light is evidence that : A. The speed of light is very large B. light is a transverse wave C. light is electromagnetic in character D. Light is a wave phenomenon
Last Answer : D. Light is a wave phenomenon
Description : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz
Last Answer : D. 300 – 3000 MHz
Description : What is the speed of electromagnetic energy traveling through air?
Last Answer : Approximately the speed of light (162,000 nautical miles per second).
Description : The spectral region of the electromagnetic radiation which passes through the atmosphere without much attenuation is known as: (A) Ozone hole (B) Atmospheric window (C) Ozone window (D) Black hole
Last Answer : Answer: Option B
Description : i) Explain electromagnetic spectrum with neat diagram. ii) Explain atmospheric noise with example.
Last Answer : Explanation:- The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths The electromagnetic spectrum covers ... spread over the complete frequency spectrum used for radio communication. Example: Lightning
Description : Select the arrangement of electromagnetic radiation which starts with the lowest energy and increases to greatest energy? A. radio, visible, infrared, ultraviolet, x-ray, gamma ray B. radio, infrared, visible ... -ray, gamma ray D. radio, infrared, visible, ultraviolet, x-ray, gamma ray (Answer)
Last Answer : D. radio, infrared, visible, ultraviolet, x-ray, gamma ray (Answer)
Description : hat is the name of the process whereby waves travel around corners and obstacles in their paths? A. Reflection B. Refraction C Interference D. Diffraction
Last Answer : D. Diffraction
Description : What characteristic(s) of radiated energy is (are) altered to achieve electronic scanning?
Last Answer : Frequency or phase.
Description : Electromagnetic radiation is hazardous to personnel in what two ways?
Last Answer : Rf burns and biological, thermal, and neurological effects.
Description : The mode theory uses electromagnetic wave behavior to describe the propagation of the light along the fiber. What is a set of guided electromagnetic waves called?
Last Answer : Modes of the fiber.
Description : 1. How many orangutans disappear each year as result of palm oil farming? 2. Who decides about the reasonableness of the restrictions placed on Fundamental Rights? 3. Microwaves are electromagnetic waves with ... 19. Where is Over 90% of the world's biomass? 20. Who deciphered the Brahmi script?
Last Answer : Answer : 1. 5000 2. Courts 3. Giga hertz 4. Tundra region 5. Kharavela 6. MRF 7. Lillehammer 8. Javan rhino 9. Evergreen forests 10. Prakrit 11. Directive Principle 12. An atom 13. Rs. 100 ... 16. Arati Saha 17. A greater flamingo 18. Finance Bills 19. In tropical rain forests 20. James Princep
Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced to zero. What will be the effect on Bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect
Last Answer : (c) Bands will disappear
Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect
Last Answer : B) BANDWIDTH DECREASES
Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the thin film is replaced by the film of higher refractive index. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will merge (d) There will not any effect
Last Answer : (b) Bandwidth decreases
Description : What organization has published safety guidelines for the maximum limits of RF energy near the human body? A. The American National Standards Institute (ANSI). B. The Environmental Protection ... Communications Commission (FCC). D. The Institute Of Electrical and Electronics Engineers (IEEE).
Last Answer : A. The American National Standards Institute (ANSI).
Description : What interaction causes energy to travel down a waveguide?
Last Answer : The interaction of the electric and magnetic fields.
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 : Electromagnetic radiation: (A) Produces a time varying magnetic field and vice versa (B) Once generated, remains self-propagating (C) Is capable to travel across space (D) All of these
Last Answer : Answer: Option D
Description : Which of the following is an undesirable characteristic of a refrigerant? (A) It should be non-explosive (B) It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils (C) Its vapor pressure at the condenser temperature should be very high (D) None of these
Last Answer : (B) It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils
Description : . What characteristic of an RL circuit allows it to act as an integrator?
Last Answer : The ability of the inductor to oppose a change in current.
Description : What characteristic of sound enables a person to distinguish one musical instrument from another, if they are all playing the same note?
Last Answer : Quality.