Description : What was the reason sculptures found in guatemala were magnetized in 11 'potbelly sculptures, six heads and five bodies?'?
Last Answer : Ancient stone "potbelly" sculptures on display in a park in Guatemala are magnetized on certain spots, suggesting the pre-Columbian civilization that made them had a practical knowledge of ... . Previous studies of the sculptures had suggested several had magnetic anomalies on their surfaces.
Description : After using a tape that was stored in an area where temperatures exceeded 130º F you notice pieces of oxide sticking to the recorder's tape-transport mechanism, to its magnetic heads, and onto the tape. What is the probable cause of these symptoms?
Last Answer : Oxide shedding. At temperatures above 130º F, oxide coating becomes soft and sheds.
Description : As an armature revolves within a magnetic field, friction is developed between the rotated magnetized particles as they pass through each magnetization cycle. This results in ____________. A. copper loss B. eddy-current loss C. hysteresis loss D. armature reaction
Last Answer : Answer: C
Description : . How do tape transports with differential velocity capstans maintain a constant tape tension in the area around the magnetic heads?
Last Answer : The supply capstan is slightly larger than the take-up capstan. This causes the take-up capstan to pull the tape slightly faster than the supply capstan feeds the tape.
Description : How often should you demagnetize a recorder's magnetic heads?
Last Answer : Every 8 to 25 hours depending on the manufacturer's recommendations.
Description : What type of equipment should you use to demagnetize your recorder's magnetic heads?
Last Answer : A hand-held degausser like the manual degaussers used for degaussing magnetic tape.
Description : How should you clean your recorder's magnetic heads?
Last Answer : With a cotton-tipped applicator soaked in either isopropyl alcohol or a head cleaner recommended by the recorder's manufacturer.
Description : Magnetic tape recorders can have up to three different heads installed. What are the three functions performed by a recorder's heads?
Last Answer : Record, reproduce, and erase.
Description : In the actuator arm assembly of a hard disk drive transport, what device can position the magnetic heads to the correct track of a hard disk more accurately than a dc stepper motor?
Last Answer : Voice coil servo.
Description : What part of a floppy disk drive transport uses a dc stepper motor to position the magnetic heads over the recording surface of a floppy disk?
Last Answer : Actuator arm assembly.
Description : What are the three functions of the magnetic heads on a magnetic recording device?
Last Answer : a. Record the signal onto the recording medium. b. Reproduce the signal from the recording medium. c. Erase the signal from the recording medium.
Description : Are paper clips picked up by a magnet permanently magnetized?
Last Answer : The paper clips will retain a weak magnetic field, and could beclassified as temporary magnets, but not permanent magnets. Thatweak field the paper clips hang on to will dissipate in time.
Description : In the process of magnetization of a bar (1) The entire bulk of the bar gets magnetized (2) Only the surface of the bar gets magnetized (3) Only the ends of the bar get magnetized (4) Only some parts of the outer layers of the bar get magnetized
Last Answer : (1) The entire bulk of the bar gets magnetized Explanation: In classical electromagnetism, magnetization or magnetic polarization is the vector field that expresses the density of permanent or induced magnetic ... the process of magnetization of a bar, the entire bulk of the bar gets magnetized.
Description : ____________ is a type of non-volatile memory composed of a thin layer of material that can be easily magnetized in only one direction. A. Bubble memory B. RAM C. SRAM D. None of the Above
Last Answer : A. Bubble memory
Description : The phenomenon of magnetostriction occurs when a ferromagnetic substance is magnetized resulting in (a) Heating (b) Small changes in its dimensions (c) Small changes in its crystal structure (d) Some change in its mechanical properties
Last Answer : The phenomenon of magnetostriction occurs when a ferromagnetic substance is magnetized resulting in Small changes in its dimensions
Description : When a ferromagnetic substance is magnetized, small changes in dimensions occur. Such a phenomenon is known as
Last Answer : When a ferromagnetic substance is magnetized, small changes in dimensions occur. Such a phenomenon is known as Magnetostriction.
Description : Why are record heads always placed before reproduce heads on recorders?
Last Answer : Allow you to monitor the signals you're recording.
Description : Most record and reproduce heads are in one of what three bandwidth categories?
Last Answer : a. Narrowband—100 Hz to 100 kHz. b. Intermediate band—100 Hz to 500 kHz. c. Wideband—400 Hz to 2 mHz.
Description : What two specifications determine the maximum frequency that a recorder's record and reproduce heads will be able to transfer?
Last Answer : a. Size of the headgap. b. Speed of the magnetic tape.
Description : The head arm assembly of a floppy disk drive transport has how many read heads and how many write heads?
Last Answer : Two read heads and two write heads.
Description : When magnetic tapes are ruined, what three factors are normally the cause?
Last Answer : Poor handling, improper storage, or shipping damage.
Description : When the relative humidity is below 10%, what happens to magnetic tape and parts of a tape recorder that could cause environmental damage?
Last Answer : Dirt build-up caused by static electricity.
Description : What are the four basic parts of a magnetic tape recorder's tape transport system?
Last Answer : a. Tape reeling system. b. Tape speed control system. c. Electronic subsystem. d. Basic enclosure.
Description : List four factors that can degrade the frequency response of magnetic tape recorders.
Last Answer : a. A too-high or too-low bias signal level setting for the record head. b. An improper reproduce head gap. c. An improper tape transport speed. d. Poor tape-to-head contact.
Description : List four rules you should follow when storing magnetic tape to protect it from damage.
Last Answer : a. Make sure the tape is wound properly on the reel hub, b. store tapes vertically, c. keep storage area at right temperature and humidity, d. store away from equipment that generates stray magnetic fields.
Description : What are four types of tape errors that can degrade a magnetic recording system’s performance?
Last Answer : Signal dropout, noise, skew, and level. Dropout is the most common.
Description : What is the number of read-write heads in the drive for a 9- trac magnetic tape? A) 9 B) 16 C) 18 D) 27
Last Answer : Answer : A
Description : What is the number of read-write heads in the drive for a 9-trac magnetic tape? a. 9 b. 16 c. 18 d. 27
Last Answer : 27
Last Answer : a. 9
Description : Motors, switches, voltage regulators, generators, etc., are a few examples of emi sources. What type of emi comes from these sources?
Last Answer : Man-made.
Description : Thunderstorms, snowstorms, cosmic sources, the sun, etc., are a few examples of emi sources. What type of emi comes
Last Answer : Natural.
Description : What are the two main sources of emi with which radio waves must compete?
Last Answer : Natural and man-made interference.
Description : Which types of LEDs are the preferred optical sources for short-distance, low-data-rate fiber optic systems?
Last Answer : SLEDs and ELEDs.
Description : Which semiconductor sources (LD or LED) emit more focused light and are capable of launching sufficient optical power into both single mode and multimode fibers?
Last Answer : LDs.
Description : Compare the power sources of synchros and step transmission systems.
Last Answer : Synchros use ac; step transmission uses dc.
Description : Microbend loss is caused by microscopic bends of the fiber axis. List three sources of microbend loss.
Last Answer : Uneven coating applications, improper cabling procedures, and external force.
Description : What meters operate from their own power sources?
Last Answer : Self-excited.
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 : You see a build-up of dust and lint on the take-up reel of a tape recorder. This can cause which of the four types of tape errors?
Last Answer : Signal dropout errors and level errors. The dust and lint on the reel will eventually get onto the tape where it can get between the tape and the recorder’s heads.
Description : I share people who you love. My fifth letter is in letter but not in mutt. if you cut off two heads I become what you do to hit some one with a weapon. I can have designes but I might be ... something that is really important not to do. I rhyme with two words in this riddle. What am I? -Riddles
Last Answer : Frame.
Description : I have Three or Four Silver Heads, My tail is sort of long. What am I? -Riddles
Last Answer : A Fork! (Three or Four Prongs; The handle is the Tail)
Description : What has six legs, two heads, four ears, two hands, but walks on four feet? -Riddles
Last Answer : A horse and rider.
Description : Reciprocating pumps (A) Are not suitable for variable heads (B) Are four times costlier than centrifugal pumps (C) Are not suitable for pumping water containing sediments (D) Single stroke produce pulsating flow
Last Answer : (A) Are not suitable for variable heads
Description : . What primary condition must magnetic lines of force meet in order to exist?
Last Answer : Magnetic lines of force must form a continuous closed loop.
Description : When the magnetic field of the inductor is completely collapsed, where is the energy of the tank circuit stored?
Last Answer : . Capacitor.
Description : List two common usages of magnetic amplifiers
Last Answer : Servosystems, temperature recorders, or power supplies
Description : What is used to bias a magnetic amplifier so that the control winding remains free to accept control (input) signals?
Last Answer : A bias winding and associated circuitry.
Description : What is the purpose of the rectifier in a magnetic amplifier?
Last Answer : The rectifier eliminates hysteresis loss.