Description : The electron beam in a CRT is made to sweep from left to right across the screen. What tube element causes this sweeping motion?
Last Answer : The horizontal-deflection plate.
Description : State one requirement of an electron tube, which does not exist for semiconductors, that makes the tube less efficient than the semiconductor.
Last Answer : The electron tube requires filament or heater voltage, whereas the semiconductor device does not; consequently, no power input is spent by the semiconductor for conduction.
Description : In an electron tube regulator, the electron tube replaces what component?
Last Answer : Variable resistor.
Description : How is the electron beam of a three-cavity klystron accelerated toward the drift tube?
Last Answer : A large negative pulse is applied to the cathode.
Description : What is the most accurate method of determining the condition of an electron tube?
Last Answer : Testing the tube in its circuit
Description : How does normal wear cause tape failure?
Last Answer : Repeated contact with a recorder’s fixed surfaces such as magnetic heads, tape rollers, and tape guides.
Description : What is the most common type of hard disk failure?
Last Answer : Head-crash.
Description : The FET and the vacuum tube have what in common?
Last Answer : Voltage controls conduction.
Description : Which of the following drugs cause death by common respiratory failure due to overdose? (a) Marijuana (b) Reserpine (c) Heroin (d) Mathadrine
Last Answer : Ans:(c)
Description : The most common cause of porosity in porcelain jacket crowns is, A. Moisture contamination B. Excessive firing temperature C. Failure to anneal the platinum matrix D. Excessive condensation of the porcelain E. Inadequate condensation of the porcelain
Last Answer : E. Inadequate condensation of the porcelain
Description : The most common cause of RCT “Root Canal Treatment” failure is: A. The canal not filled completely (Short obturation) B. Over filled canals
Last Answer : A. The canal not filled completely (Short obturation)
Description : The most common cause of failure of the IDN “Inferior Dental Nerve” block is, A. Injecting too low B. Injecting too high
Last Answer : A. Injecting too low
Description : When you are measuring a component using a bridge, what is the most common cause of inaccurate measurements?
Last Answer : The capacitive and inductive characteristics of the test leads.
Description : Tape winding errors can cause a deformed tape pack. What are four common types of tape pack deformation?
Last Answer : Cinching, pack slip, spoking, and windowing.
Description : What are four main causes of tape failure?
Last Answer : Normal wear, accidental damage, environmental damage, and winding errors.
Description : What is tape failure?
Last Answer : Tape’s performance degrades to a point where it’s no longer
Description : What type of storage can retain its data even if there is a power failure or breakdown?
Last Answer : Nonvolatile (magnetic core storage and bubble memory are examples).
Description : The resonant frequency of electron wobble can be changed by variation of what force?
Last Answer : The applied magnetic field.
Description : Which of the two types of electron motion (orbital movement and electron spin) is more important in the explanation of magnetism?
Last Answer : Electron spin.
Description : What effect does closer spacing of plates have on the electron beam?
Last Answer : A greater deflection angle.
Description : What effect do longer deflection plates have on the electron beam?
Description : Why are the electrostatic fields between the electron gun elements called lenses?
Last Answer : Because they bend electron streams in much the same manner that optical lenses bend light rays.
Description : What term is used for the ability of a spot on a CRT screen to continue to glow after the electron bean has struck it and moved away?
Last Answer : Persistence.
Description : What are two advantages that gas-filled tubes have over conventional electron tubes?
Last Answer : a. They can carry more current. b. They maintain a constant IR drop across the tube
Description : Why is electron flow with the arrow in the symbol of a Zener diode instead of against the arrow as it is in a normal diode?
Last Answer : Because Zener diodes are operated in the reverse bias mode.
Description : What term is used to describe the definite discrete amounts of energy required to move an electron from a low shell to a higher shell?
Last Answer : Quanta.
Description : What type of deflection is preferred for a crt electron beam?
Last Answer : . Electromagnetic.
Description : What type of electron-resonance anode block does not require strapping?
Last Answer : Rising-sun block.
Description : What element in the magnetron causes the curved path of electron flow?
Last Answer : The permanent magnet.
Description : What relationship must exist between the electron beam and the traveling wave for bunching to occur in the electron beam of a twt?
Last Answer : The traveling wave must have a forward velocity equal to or less than the speed of the electrons in the beam.
Description : Debunching of the electron bunches in the higher modes of a reflex klystron has what effect on output power?
Last Answer : Power is reduced.
Description : The constant-speed electrons of an electron bunch in a reflex klystron must remain in the repeller field for what minimum time?
Last Answer : Three-quarter cycle.
Description : When the repealer potential is constant, what property of the electron determines how long it will remain in the drift space of the reflex klystron?
Last Answer : Velocity.
Description : What is the effect upon an electron that enters the buncher gap when the potential across the grids is at 0 volts?
Last Answer : There is no effect
Description : What portion of an electron gun causes the electrons to accelerate or decelerate?
Last Answer : The buncher grids.
Description : What will be the effect upon an electron traveling in the opposite direction to the lines of force in an electrostatic field?
Last Answer : The electron will be accelerated.
Description : The kinetic energy of an electron is directly proportional to what property?
Description : According to electron theory, an electric current flows from what potential to what potential?
Last Answer : Electron theory assumes that electron flow is from negative to positive.
Description : Why does the grid have a greater effect than the plate on electron flo
Last Answer : Because it is closer to the cathode.
Description : An electron moves into the electrostatic field between a positive charge and a negative charge. Toward which charge will the electron move?
Last Answer : Toward the positive charge.
Description : Folinic acid is specifically indicated for: A. Prophylaxis of neural tube defect in the offspring of women receiving anticonvulsant medication B. Counteracting toxicity of high dose methotrexate C. Pernicious anaemia D. Anaemia associated with renal failure
Last Answer : C. Pernicious anaemia
Description : Ohm’s law obeyed in - (1) a metallic conductor (2) a semi conductor (3) an electron tube (4) in all of the above
Last Answer : (1) a metallic conductor Explanation: There are, however, components of electrical circuits which do not obey Ohm's law; that is, their relationship between current and voltage (their I–V curve) is nonlinear (or non-ohmic).
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
Last Answer : Answer: D
Description : A color television set employs a 25,000 volt electron accelerator to produce the picture and potentially harmful radiation which must be shielded against. The main component of this radiation consists ... which penetrate the picture tube x) soft x-rays y) microwaves z) ultraviolet radiation
Last Answer : ANSWER: X -- SOFT X-RAYS
Description : What type of uhf tube was developed to handle large amounts of power?
Last Answer : Planar
Description : The end of the usefulness of a tr tube is indicated by an increase in what quantity?
Last Answer : Recovery time.
Description : What type of tube best meets the requirements of a modulator switching element?
Last Answer : Thyratron.
Description : In a series-connected duplexer, what tube (tr or atr), if any, fires during the receive cycle?
Last Answer : Neither fires.