Description : The process, whereby electrons gain sufficient energy to be released from the surface of a thin, heated metal plate, is known as _____________. A. photo electric emission B. secondary emission C. thermionic emission D. regressive emission
Last Answer : Answer: C
Description : The source of the sun's energy is the process of – (1) Photoelectric emission (2) Nuclear fission (3) Nuclear fusion (4) Thermionic emission
Last Answer : (3) Nuclear fusion Explanation: The Sun formed about 4.6 billion years ago from the gravitational collapse of a region within a large molecular cloud. Most of the matter gathered in the center, ... thermonuclear fusion in its core. It is thought that almost all other stars form by this process.
Description : The source of the Sun's energy is the process of – (1) Photoelectric emission (2) Nuclear fission (3) Nuclear fusion (4) Thermionic emission
Last Answer : (3) Nuclear fusion Explanation: Nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. During this process, matter ... fusing nuclei is converted to energy which is released. Fusion is the process that powers active stars.
Description : The source of the Sun’s energy is the process of (1) Photoelectric emission (2) Nuclear fission (3) Nuclear fusion (4) Thermionic emission
Last Answer : Nuclear fusion
Description : Quartz crystal in quartz watches work on the principle called? A. Photoelectric effect B. Stark effect C. Thermionic effect D. Piezo-electric effect (Answer) E. None of these
Last Answer : D. Piezo-electric effect (Answer)
Description : The basic operating principle of a transformer is attributed to ______________. A. electromagnetic induction B. variance of a conductor in a magnetic field C. mutual reaction D. thermionic emission
Last Answer : Answer: A
Description : Impressed current cathodic protection is used on vessels instead of _________________. A. fire alarm systems B. repeated painting C. sacrificial zincs D. vacuum tube degaussing systems
Description : In an impressed current cathodic protection system, the anode is ____________. A. connected to the hull and deteriorates with time B. insulated from the hull and does not waste away C. connected to the hull but does not waste away D. insulated from the hull but deteriorates with time
Last Answer : Answer: B
Description : What are the differences between thermionic emission and evaporation?
Last Answer : Thermionic emission occurs when electron leaves the surface of metals while evaporation occur in liquid when strong electron gain energy and escape the liquid surface in gaseous form
Description : The phenomenon of nuclear fission is opposite to that of (A) Radioactive decay (B) Thermionic emission (C) Nuclear fusion (D) Combustion
Last Answer : (C) Nuclear fusion
Description : Define Thermionic emission.
Last Answer : The process by which free electrons are emitted from the surface of a metal when external heat energy is applied is called thermionic emission. Thermionic emission occurs in metals that are heated to a very ... of external energy in the form of heat is supplied to the free electrons in the metals.
Description : List any two applications of thermionic emission.
Last Answer : 1. The components which are made by the process of thermionic emission are used in the electronic devices such as cathode ray tube, radio etc. 2. Thermionic emission are used in a ... , power electronics, x-ray generation, and energy converters from high-temperature sources and solar energy.
Last Answer : Thermionic emission occurs in vacuum tubes.
Description : A circuit which develops voltage across the horizontal deflection plates is known as a) Time base generator b) Electron gun c) Thermionic diode d) Zener diode
Last Answer : a) Time base generator
Description : The reverse effect of X-ray emission is (1) Raman effect (2) Compton effect (3) Zeeman effect (4) Photoelectric
Last Answer : (4) Photoelectric Explanation: When fast moving electrons strike on high atomic weight substance, X - ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency ... and electrons are emitted. Hence, X ray is the inverse phenomenon of photoelectric effect.
Description : Light waves can cause photoelectric emission in a) Metals b) Alkali metals c) Insulators d) None of the above
Last Answer : c) Insulators
Description : The reverse effect of X–ray emission is (1) Raman effect (2) Compton effect (3) Zeeman effect (4) Photoelectric
Last Answer : Photoelectric
Description : Which of the following statements comparing transistors and vacuum tubes is correct? A. Both transistors and vacuum tubes have a cathode that must be heated to give off electrons. B. A vacuum tube must ... flow. D. The anode of both transistors and vacuum tubes must be heated to give off electrons.
Description : Heat sinks are frequently used with _____________. A. power transistors B. vacuum tubes C. tunnel rectifier diodes D. all of the above
Description : A convection process in which an external device, such as a fan, is used to produce the fluid flow. a. Forced Convection b. External Convection c. Placid Convection d. Thermionic Convection
Last Answer : Forced Convection
Description : Moisture accumulating in electric motors and generator windings having a cold insulation resistance greater than 50,000 ohms may be baked out with internal heat. This heat can be developed by ____________. ... an electric welder and feeding it into the armature while running the motor at full speed
Description : The schematic diagram shown in the illustration represents which of the listed solid-state circuits? EL-0069 A. Bridge rectifier B. Magnetic amplifier C. Flip-flop generator D. Cathodic amplifier
Description : The circuit shown in the illustration represents a ________. EL-0090 A. battery charging circuit B. synchronous exciter C. depth sounding unit D. cathodic protection system
Last Answer : Answer: D
Description : What precaution should be taken with a vessel's impressed current cathodic protection system after a drydocking period during which the hull has been painted? A. Output currents should be carefully monitored ... slight (10-15%) overcurrent to the anodes should be allowed in order to speed drying.
Description : The amount of current flow required for the cathodic protection of a vessel is dependent upon the _________. A. amount of bare steel surface B. speed of the ship through the water C. temperature of the water D. all of the above
Description : For more complete vessel protection when using an impressed current cathodic system _____________. A. all ship's service alternators have additional temperature sensing devices and a thermal recorder ... with the hull and the propeller shaft is grounded through a slip ring/brush arrangement
Description : The purpose of an impressed current cathodic protection system aboard ship is to _______________. A. prevent corrosion of the hull, propeller, rudder and line shafting B. neutralize the vessel's ... the presence of salt air D. maintain a minimum constant alternator load to prevent overheating
Description : Which of the following represents the accepted method of cleaning dust and foreign particles from electrical equipment while limiting damage to electric components? A. Carefully wiping off the components ... the components. D. Using carbon tetrachloride as a cleaning solvent to clean the components.
Description : Sacrificial anode method is used in the protection of pipelines which are buried underground. Sacrificial anode (A) Occurs higher in the electro-chemical series of metals (B) Is exemplified by magnesium plate (C) ... cathodic base material to be guarded against corrosion (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding ... . making sure that the units are close to bulkheads or corners to protect them from damage
Description : The main difference between an electron tube and a transistor is the _____________. A. type of function they can perform B. reaction of electron flow through a gas or vacuum in a transistor C. ... when placed in a tube D. reaction of electron flow through a semiconductor used to form a transistor
Description : All electric cables passing through watertight bulkheads must be _____________. A. installed with watertight stuffing tubes B. grounded on both sides of the bulkhead C. fitted with unions on each side of the bulkhead D. welded on both sides of the bulkhead
Description : Before using an all-purpose electric measuring instrument (multimeter) utilizing internal batteries to supply power for resistance measurements, you should FIRST ____________. A. remove one of the ... batteries C. calibrate using a known external resistance D. select the proper resistance range
Description : If a transformer is connected to a DC source, the transformer will overload at the ____________. A. contacts B. primary coil C. secondary coil D. core
Description : Increasing the load to the secondary windings of a transformer will cause a/an ____________. A. decrease in the primary voltage B. increase in the primary voltage C. decrease in the primary current D. increase in the primary current
Description : A photoelectric cell converts – (1) Mechanical energy to electric energy (2) Heat energy to mechanical energy (3) Light energy to chemical energy (4) Light energy to electrical energy
Last Answer : (4) Light energy to electrical energy Explanation: Photoelectric cell or photocell, device whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is incident ... The most common type consists of two electrodes separated by a light-sensitive semiconductor material.
Description : Photoelectric electricity is produced directly from solar energy when which of the following are absorbed in a semiconductor to create an electric current? w) protons x) electrons y) neutrons z) photons
Last Answer : ANSWER: Z -- PHOTONS
Description : Does anybody make vacuum tubes anymore? All I ever find are surplus.
Last Answer : answer:Without details as to type, there are over 39,000 currently listed on eBay. I’d say they’re still manufactured since there’s also availability on Amazon.
Description : Why vacuum tubes are not preferred at microwave?
Last Answer : Actually three special purpose vacuum tubes were specifically designed for microwave usage and are in some cases still the least expensive way to work with high power microwave signals.These ... and the electromagnetic compatibility (EMC) testing industry for immunity testing of electronic devices)
Description : Which of the following is not a feature of first generation computers A) They used vacuum tubes or valves as main electronic component B) They consumed lots of electricity and produced excessive heat C) They used machine language and assembly language to program the machine D) None of above
Last Answer : Answer : C
Description : First generation computers used for memory A) vacuum tubes B) silicon chips C) magnetic drum D) RAM
Description : Which electronic component was made out of semiconductor material? A) Vacuum tubes B) Transistors C) ICs D) All of above
Description : Who invented vacuum tubes? A) John Bardeen B) William Shockley C) Lee de Forest D) All of above
Description : What was the main disadvantage of vacuum tubes? A) They were larger in size B) They consumed a lot of electricity C) They produced heat and often burned out D) The operation cost was high
Description : Why are vacuum tubes also called valves? A) Because they can amplify the weak signals and make them strong B) Because they can stop or allow the flow of current C) Both of above D) None of above
Last Answer : Answer : B
Description : The main electronic component used in first generation computers was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above
Description : Chief component of first generation computer was A) Transistors B) Vacuum Tubes and Valves C) Integrated Circuits D) None of above
Description : First Generation computers used ______ for Circuitry and ________ for memory (A) Transistor and Magnetic Core (B) IC and Magnetic Memory (C) Vacuum tubes and Magnetic drum (D) IC and Magnetic Core
Last Answer : (C) Vacuum tubes and Magnetic drum
Description : The HPAs in most satellite are A. TWTs B. Klystrons C. Vacuum tubes D. Magnetrons
Last Answer : A. TWTs
Description : Vacuum tubes have been replaced by-----? A. Conductors B. Diodes C. Transistors (Answer) D. None of these
Last Answer : C. Transistors (Answer)