Description : How do closed-loop capstan drive tape transports overcome the disadvantages of the open-loop drive design?
Last Answer : Closed loop capstan drive transports use more than one capstan to clamp the tape in the area around the magnetic head.
Description : What are the three most common closed-loop capstan drive designs?
Last Answer : a. Differential velocity capstans. b. Dual motors dual capstans. c. Peripheral drive capstans.
Description : How do dual-motor dual capstan drives maintain a constant tape tension while operating in either a forward or reverse direction?
Last Answer : Each capstan is driven by its own motor. It maintains tape tension by slowing down one of the motors. When the tape motion is reversed, the opposite motor is slowed down.
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 : Why open loop OP-AMP configurations are not used in linear applications?
Last Answer : The open loop gain of the op-amp is not a constant and it varies with changing the temperature and variations in power supply.Also the bandwidth of the open loop op-amp is negligibly small.For this reasons open loop OP-AMP configurations are not used in linear applications.
Description : Closed loop and Open loop Control System Advantages and Disadvantages
Last Answer : Open Loop Control System: Control System in which output quantity has no effect on the input quantity is called Open Loop Control System. Open Loop Control System has no facility to correct automatically the ... in the closed loop system and more care is needed to design a stable closed loop system
Description : Hard disk drive transports contain the electromechanical parts that perform what three functions?
Last Answer : a. Rotates the hard disk platters. b. Writes data to and reads data from the disk platters
Description : What basic requirement of a closed-loop system (not present in open-loops) enables present load position to be sensed?
Last Answer : Feedback.
Description : What two transistor amplifier configurations are combined in the single-transistor, two-input, single-output difference amplifier?
Last Answer : Common emitter (CE) and common base (CB)
Description : In describing a switch by the number of positions of the actuator, what are the two possible configurations for a single pole, double-throw switch?
Last Answer : Two-position and three-position.
Description : What term is used to identify each of the many field configurations that can exist in waveguides?
Last Answer : Mode of operation.
Description : What are the three transistor configurations?
Last Answer : Common emitter (CE), common base (CB), and common collector (CC)
Description : What are the three basic configurations of transistor oscillators?
Last Answer : Common collector (CC), common emitter (CE), and common base (CB).
Description : select the correct response from the choices given in the parentheses. Q-20. In a closed-loop configuration the output signal is determined by (the input signal, the feedback signal, both).
Last Answer : Both the input signal and the feedback signal.
Description : What does the term "closed-loop" mean in the closed-loop configuration of an operational amplifier?
Last Answer : The use of degenerative (negative) feed-back
Description : What is the advantage of using a closed-servo loop to control load velocity?
Last Answer : The closed-servo loop can regulate load speed under changing conditions.
Description : What are two disadvantages of using a recorder’s erase head to erase data recorded on a magnetic tape?
Last Answer : Using an erase head is slow, and it may not completely erase the tape.
Description : What equipment should you use to de-magnetize a magnetic tape transport?
Last Answer : A hand-held degausser.
Description : When cleaning the parts of a tape transport, why should you switch lint-free cloths and swabs often?
Last Answer : You may transfer dirt or oxide particles from one part of the tape transport to another
Description : Sometimes it's necessary, but why should you avoid using cotton swabs when cleaning a magnetic tape transport?
Last Answer : Cotton swabs are not lint free.
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 : How do worn or sticking tape transport guides cause dynamic skew on a multi-track recorder?
Last Answer : The tape drifts past the multi-track head at an angle.
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 : Assertion `:-` The blood transports carbondioxide comparatively easily. Reason `:-` During `CO_(2)` transport chloride ions diffuse from plasma into t
Last Answer : Assertion `:-` The blood transports carbondioxide comparatively easily. Reason `:-` During `CO_(2)` ... D. If both Assertion & Reason are false.
Description : Active and passive transports across cell membrane differ in (a) passive transport is nonselective (b) passive transport is along the concentration gradient while active transport is due to metabolic ... (d) passive transport is confined to anions while active transport is confined to cations.
Last Answer : (b) passive transport is along the concentration gradient while active transport is due to metabolic energy
Description : Which of the following statement(s) is/are true concerning carrier proteins? a. Carrier proteins are distinguished by three types of mechanisms: carrier-type, channel-type, and conduction-type b. ... and open d. Carrier-type transport proteins are equally accessible from either side of the membrane
Last Answer : Answer: b, c Most transport proteins appear to function as carriers, rather than channels. Important distinctions can be made between types of carrier proteins on the basis of transport kinetics. ... a carrier mechanism, the binding site is available only one side of the membrane at any instant
Description : What are the disadvantages of Open loop control system?
Last Answer : Open loop control system are less reliable. In open loop control system Optimization is not possible. Open loop control system are less accurate.
Description : With reference to NC machines, which of the following statements is wrong a.Both closed-loop and open-loop control systems are used b.Paper tapes, floppy tapes and cassettes are used for data storage c.Digitizers may be used as interactive input devices d.Post processor is an item of hardware
Last Answer : c.Digitizers may be used as interactive input devices
Description : In which system we get feedback? a.Open-loop system b.Machine control system c.Closed-loop system d.None of the above
Last Answer : c.Closed-loop system
Description : Explain Closed loop and Open loop system with sketch.
Last Answer : Closed Loop System: [1] The name indicates that the closed loop control system has a loop that is closed as shown in figure. [2] A feedback device is used for this purpose. This makes ... system is generally used in point-to-point systems where the accuracy requirements are not critical.
Description : Describe open loop and closed loop system.
Last Answer : Open loop and closed loop system: Open system: When the input is independent of the output, the system is called open- loop system. The control action is based on only some ... system is called closed- loop control system. The output is continuously measured and fed to the input.
Description : Difference between open loop and closed loop control system
Last Answer : Difference between open loop and closed loop control system : Sr No. Open loop control system Closed loop control system 1 Feedback doesn't exists Feedback exists 2 ... and hence costly 9 Highly affected by nonlinearities Reduced effect of non-linearity
Description : Order of the open loop transfer function is _____ to order of closed loop transfer function (a) not equal (b) equal (c) less than (d) greater than
Last Answer : Order of the open loop transfer function is equal to order of closed loop transfer function
Description : An OP amp has an open loop gain of 1,00,000. If the feedback fraction is 0.02, the approximate closed loop gain is (a) 1 (b) 1,00,000 (c) 50 (d) 0.02
Last Answer : The closed loop gain Ag = G/(1+G*f) Where G is the open loop gain and f is the feedback fraction So Ag = 49.975
Description : In an open-loop control system, what action reduces the input to zero so the load is stopped at the desired position?
Last Answer : Usually the operator senses the desired load movement and reduces the input to stop the motor.
Description : What are the major differences between magnetic tape units?
Last Answer : The speed at which the tape is moved past the read/write head and the density of the recorded information.
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 contains the circuitry which controls the electromechanical parts of the transport?
Last Answer : Drive electronics circuit board.
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 : 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 : What are the four most important parts of a floppy disk drive transport?
Last Answer : a. Drive motor/spindle assembly. b. Head arm assembly. c. Actuator arm assembly. d. Drive electronics circuit board.
Description : Name two major disadvantages of transistors.
Last Answer : Sensitive to heat and minor overloads.
Description : What is one of the major disadvantages of multilayer printed circuit boards?
Last Answer : Difficulty of repair of internal connections.
Description : What are the two primary disadvantages of a two-wire open line?
Last Answer : High radiation losses and noise pickup.
Description : What is Capstan or Tarot Led ?
Last Answer : Capstan or Tarot Led is just an improved version of Center Led. Capstan or torret lead is a type of lead that is made instead of engine stock for the purpose of rapid production.
Description : What is the difference between the first officer and the capstan?
Last Answer : What is the answer ?
Description : On tank vessels with an electrically-driven capstan, the motor should be meggered periodically to test _____________. A. insulation resistance B. eddy currents C. capacitance D. armature reactance
Last Answer : Answer: A
Description : Theodolite is an instrument used for (a) Tightening the capstan-headed nuts of level tube (b) Measurement of horizontal angles only (c) Measurement of vertical angles only (d) Measurement of both horizontal and vertical angles*
Last Answer : (d) Measurement of both horizontal and vertical angles*
Description : What are the terms used to describe an open or closed telegraph circuit?
Last Answer : Space and mark.