Electronics Q & A 1 PDF

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EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 What allows simplifying a one-port circuit A measure of the small-signal performance To avoid oscillation, the gain crossover to a current source in parallel with an of voltage-dependent current sources is frequency must ______the phase crossover impedance? the ______ defined as the change in the frequency. Norton’s Theorem output current divided by the change in the fall below input voltage. Charge carriers move in semiconductors transconductance In low-distortion applications, the output via two mechanisms: _____ and _______. stage may be embedded in a _____ to drift and diffusion The impedance seen looking into the gate suppress the nonlinearity. of a MOSFET is equal to ____. negative feedback loop The diffusion current density is infinity proportional to the _________ of the carrier A push-pull stage operating at high concentration The ____ topology exhibits a nominal gain temperatures may suffer from _______, gradient equal to one plus the ratio of whereby the elevated temperatures allow two resistors. The circuit also suffers from the output transistors to draw higher The ______ is the minimum energy required a gain error that is inversely proportional to currents, which in turn makes them to dislodge an electron from its covalent the gain of the op amp. dissipate even more. bond. noninverting amplifier thermal runaway bandgap energy Placing a bipolar device around an op amp The ______ response provides a sharper Under a high reverse bias voltage, pnpn provides a ______function. transition than Butterworth at the cost of junctions break down, conducting a very logarithmic some ripple in the passband and high current. Depending on the structure stopbands. It contains n complex poles on and doping levels of the device, ____ Op amps suffer from various an ellipse. breakdown may occur. imperfections, including dc offsets and Chebyshev Zener and Avalanche input bias currents.These effects impact the performance of various circuits, most A phenomenon that occurs for large The statement” A voltage-dependent notably, _____. reverse voltages across a pn junction current source can form an amplifier along integrators where the free electrons are accelerated to with a load resistor” is _____. such high speeds that they can dislodge True Stacking a transistor atop another forms a valence electrons. _______ structure, resulting in a high output Avalanche effect For proper operation, the _____ is forward- impedance. biased and the _______ is reverse-biased. cascade A graph showing the gain or phase base-emitter junction, base-collector performance of an electronic circuit at junction Bipolar differential pairs exhibit a _____ various frequencies. input/output characteristic. The tail current Bode plot The ________ of the bipolar transistor can be mostly steered to one side with a consists of an exponential voltage- differential input of about 4Vt. What do you call the ohmic resistance of dependent current source tied between hyperbolic tangent the semiconductor? the collector and emitter, and a diode Bulk resistance (accounting for the base current) tied As the frequency of operation increases, between the base and emitter. capacitances exhibit a _______, reducing It is a comparator with hysteresis. large-signal model the gain. The gain thus rolls off at high Schmitt trigger signal frequencies. The ______ stage provides a moderate lower impedance The metaphor used to describe the action voltage gain, a moderate input impedance, of an SCR when it is used to protect a load and a moderate output impedance. To obtain the frequency response, we must against supply. common-emitter derive the _____ of the circuit. Crowbar transfer function The _____ provides a voltage gain less than A value that tells you how much to reduce unity, a high input impedance, and a low The ________of a feedback system can, in the power rating for each degree above the output impedance, serving as a good principle, be obtained by breaking the loop, reference temperature given on the data voltage buffer injecting a test signal, and calculating the sheet. emitter follower gain as the signal goes around the loop. It Derating factor determines many properties of feedback MOSFETs operate in the ______ region if the systems, e.g., gain, frequency response, It is the process of adding impurity element drain voltage is more than one threshold and I/O impedances. to an intrinsic semiconductor to change its below the gate voltage loop gain conductivity. triode Doping A condition where the transistor is A capacitance tied between the input and operating at the upper end of the load line The pattern appearing on an oscilloscope output of an inverting amplifier appears at with a base current that is one-tenth of the when harmonically related signals are the input with a factor equal to one minus collector current. applied to the horizontal and vertical the gain of the amplifier. This is called ____. Hard saturation inputs. Miller effect Lissajous’ pattern Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 A connection of two transistors connected Atom with four valence electrons is called A logic gate that produces a HIGH output with positive feedback to simulate the ______. only when its two inputs are at opposite action of a thyristor. tetravalent levels. Latch XOR The term applied to any semiconductor It refers to the average amount of time material that has been carefully refined to The complement of a sum of variables is between the creation and recombination of reduce the number of impurities to a very equal to the product of the complements a free electron and a hole. low-essentially as pure as can be made of the variables. Life time available through modern technology. De Morgan’s Theorems Intrinsic A filter that blocks a signal with at most Which of the following expression is in one frequency. Who discovered electrons in 1897? standard SOP form? Notch filter Thompson F=ABC+AB’C+A’B’C’ A term used to describe the death of What is the typical energy gap of silicon In a 4 variable K-map, what is the binary amplification. semiconductor? value for the cell in the lower right corner? Oscillation 1.1eV 1010 The voltage that provides the border Which of the following semiconductor It is a digital circuit that adds two bits and between the ohmic region and the material is sensitive to temperature an input carry to produce a sum and an constant current region of a depletion- change? output carry. mode device when the gate to source Germanium Full adder voltage is zero. Pinch off voltage It occurs when a conduction-band electron Which of the following is the invalid state loses energy and falls back into a hole in for RS flip flop? A basic circuit that a designer can modify the valence band. S=1; R=1 to get more advanced circuits. Recombination Prototype In T flip flop, T stands for: Which of the following is not a pentavalent Toggle Which of the following special purpose atom? diode doesn’t have depletion layer? Boron How many flip-flop/s is/are need to Schottky diode produce 2kHz frequency from 8kHz input? How does minority carriers produced? 2 It is defined as a large initial current that Thermally produced flows through the diode of a rectifier. A flip-flop is in the toggle condition when: Surge current It is an extremely small amount of current J=1; K=1 that exists in a reverse biased diode. It is defined as a four-layer semiconductor Reversed saturated current How many flip-flops are needed to produce device that acts as a latch. 4-bit asynchronous counter? Thyristor What is the typical reverse saturated 4 current of a silicon diode? It is the value of the input voltage that 10pA How many flip-flops are needed to produce switches the output of a comparator. modulus-12 asynchronous counter? Trip point What is the typical range of reverse 4 breakdown voltage of silicon diode? It is a device that acts like two back-to- 50-1kV What do you call the number of unique back-zener diodes. states through which a counter will Varistor The time required for the minority carriers sequence? to return to the majority carrier state in the Modulus What do you call a thin slice of crystal used opposite material. as a chassis for integrated components. Storage time Asynchronous counters are known as: Wafer ripple counters What does FPGA stand for? What is the other term for zener effect? Field programmable gate array The modulus of a counter is High field emission the actual number of states in its sequence Find the 2’s complement of 10110010. It is sometimes called hot-carrier diode. 01001101 Three cascaded modulus-10 counters Schottky diode have an overall modulus of Convert the binary number 11000110 to 1000 A network that employ diodes to remove gray code away a portion of an input signal without 10100101 The terminal count of a modulus-13 binary distorting the remaining part of the applied counter is waveform Which of the following can be used as 1100 Clipper universal gate? NAND Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 The difference between the two op-amp The time sequence of inputs, outputs and For what value of ID is gm equal to 0.5 gm0? input currents is called ______. flip-flop states can be enumerated in a 0.25 IDSS Input Offset Current _______. This consists of four sections labeled the present state, input, output Which of the following transistor has A circuit whose output voltage is and next state. depletion and enhancement types? proportional to the area under the curve of state table MOSFET the input voltage. Integrator In digital design of combinational logic What is the level of IG in an FET? circuits, what do you call the term that Zero A circuit whose output voltage is refers to the connection of the output of proportional to the slope of the input one device to the input of a similar device The region to the left of the pinch-off locus voltage. allowing one device to drive the other in is referred to as the _____ region. Differentiator order to expand the operational capability? ohmic Cascading A filter response that exhibits an equiripple The drain current will always be one-fourth amplitude response in the pass band. In computers, what do you call a relatively of IDSS as long as the gate-to-source Chebyshev Response small, high-speed memory that stores the voltage is _____ the pinch-off value. most recently used instructions or data one-half A filter response that exhibits maximum from the larger but slower main memory? flatness possible in the pass band. cache memory How many terminals can a MOSFET have? Butterworth Response 3 or 4 What is the ratio of the input impedance The ____ gate is called the “all or nothing” with series feedback to that without It is the insulating layer of _____ in the gate. feedback? MOSFET construction that accounts for the AND 1 + BA very desirable high input impedance of the device. Express the Boolean function F= xy + x’z in Which of the following is required to start SiO2 a product of maxterm form. oscillation? F = (x’+y)(x+y)(y+z) Both BA > 1 and the phase shift around the The transfer curve is not defined by feedback network must be 180 degrees Shockley's equation for the _____. In switching transistors, what do you call EMOSFET the time between the changing state of the In the IC phase-shift oscillator, what input and the beginning of a response in should the ratio of feedback resistor Rf to Which of the following FETs has the lowest the output? R1 be? input impedance? Delay time Greater than -29 JFET The current gain of a common-base BJT In the Wien bridge oscillator, which of the How many orbiting electrons does the configuration is _____________. following is (are) frequency-determining germanium atom have? just less than 1 components? 32 Both resistors and capacitors The current gain of a Darlington pair is One eV is equal to _____ J. called ________. What is the typical value of quality factor 1.6 E–19 Superbeta for crystal oscillators? 20,000 What unit is used to represent the level of a A ______ is a dc–dc converter with an diode forward current? unregulated input dc voltage and a In which of the following applications is a mA regulated output voltage. The converter pulsating dc voltage suitable? circuitry consists of arrangements of Battery charger Which capacitance dominates in the inductor, capacitors, diodes, and reverse-bias region? transistors. The transistors are switched Across which of the following components Depletion between the ON state (saturation) and the of a power supply does the average (dc) OFF state (cutoff) at rates that typically voltage exist? Which capacitance dominates in the range from 10 kHz to 40 kHz. Capacitor filter forward-bias region? switched-mode power supply Diffusion What is the purpose of an additional RC Logarithmic amplifiers, together with filter section in a power supply circuit? What does a high resistance reading in exponential amplifiers are used to perform Decrease the ac voltage component both forward- and reverse-bias directions analog multiplication. These can be indicate? constructed by using an operational In a simple series regulator circuit, which An open diode amplifier and a diode. Where and how of the following components is the should the diode be placed so that the controlling element? What is the maximum power rating for circuit will work as a logarithmic amplifier? Transistor LEDs? Forward biased in the feedback path, 150 mW replacing Rf of an inverting op-amp What is the range of gm for JFETs? 1000 uS to 5000 uS * Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 The _____ diode model is employed most As electrons in the atoms of a A device that can deliver high voltage AC frequently in the analysis of electronic semiconductor material fall from higher from a low voltage DC source. systems. energy levels to lower levels inverter practical photoemission can occur These are the simplest, cheapest, and At what region of operation is the base- A thyrector can be used to most rugged form of analogue meter in emitter junction forward biased and the suppress transients in a power supply common use. base-collector junction reverse biased? Moving iron galvanometers Linear or Active When a PNP bipolar transistor is reversed biased, A resistor with an additional off-take point, For the BJT to operate in the saturation no current flows in the collector circuit either fixable or more often a wiper arm, region, the base-emitter junction must be under no signal condition which can be set at a required position, for _____-biased and the base-collector the purpose of obtaining a voltage of some junction must be _____-biased. Another name for hfe of a bipolar transistor fraction of the total voltage across the forward, forward is the whole resistor. beta pot Which of the following voltages must have a negative level (value) in any NPN bias When an oscillator is said to be unstable, It is the input variable or parameter to a circuit? this could mean that process that is varied by a control signal VBC the circuit doesn't oscillate reliably from the processor to an actuator. Manipulated variable Which of the following is referred to as the Which type of the following oscillator types reverse transfer voltage ratio? uses a quartz crystal to determine the Magnetic relay is an example of: hr frequency? Actuators Pierce Which of the following techniques can be It is the signal used to control power to the used in the sinusoidal ac analysis of A PLL frequency synthesizer actuator to set the level of the input transistor networks? has a stable signal frequency variable. Small- or Large-signal Correction signal In an Armstrong oscillator The _____ model suffers from being limited the signal is fed from the output to the It is the difference between the indicated to a particular set of operating conditions if input through a transformer value and the actual value an instrument or it is to be considered accurate. device. hybrid For a circuit to oscillate, the gain must be Accuracy high, the feedback must be positive, and What is the unit of the parameter ho of a the coupling from output to input must be This refers to the limits within which a BJT? good signal can be read and may be somewhat Siemen subjective. A twin-T oscillator is commonly used to Precision What is the typical value of the current gain generate audio signals of a common-base configuration? It is the ability of an instrument to Less than 1 The simplest power-supply filter consists repeatedly read the same signal over time, of one or more large-value capacitors, and give the same output under the same What does the negative sign in the voltage connected in parallel with rectifier output. conditions. gain of the common-emitter fixed-bias A good component for this purpose is the: Reproducibility configuration indicate? electrolytic capacitor The output and input voltages are 180º out It is the reading of an instrument with zero of phase. In power supplies, it is easier to filter input. a higher frequency pulsating DC offset The _____ configuration is frequently used for impedance matching. When a filter choke is placed on the It is the change in the reading of an emitter-follower rectifier side of the capacitor, the circuit is instrument of a fixed variable with time. choke-input filter drift A diode that is used as an envelope detector should have Suppose you want to back up the memory What is the bandgap energy for diamonds? small junction capacitance contents of a microcomputer-controlled 2.5eV device for months at a time during which A varactor can be used for the purpose of the device is not used. The current required It is the difference in readings obtained tuning a gunn-diode oscillator for this application is very low. You want when an instrument approaches a signal the battery to have low mass and small from opposite directions. The forward breakover voltage of a signal volume, and to require no maintenance. drift diode can be exploited in the design of The type of battery to be used is: a noise limiter lithium cells The icons in the computer are determined by the: extension Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 It is a measure of the closeness of Computer file types are reflected by: The noninverting amplifier has a agreement between a number of readings extension Large closed-loop input impedance taken consecutively of a variable, before the variable has time to change. The size of files in a computer is measured Why has a "unit size" for conductors been Repeatability in the unit of a: established? Byte To compare the size and resistance of one It is the temperature at which all molecular conductor with that of another motion ceases or the energy of the An empty folder in a computer has an molecule is zero. actual size of What are the two general classifications of Absolute zero 902 Bytes synchro systems? Torque and control It is the first temperature scale to gain An empty folder in a computer has a size of acceptance. 1Kbyte Artificially grown silicon or germanium Fahrenheit crystals are used to produce substrates for With a GUI (graphic user interface), we give which of the following types of integrated It is the transfer of heat due to motion of commands with three different ways circuits? elevated temperature particles in a except: material (liquid and gases). keyboard Monolithic Convection The output of an OR gate is logic 1 when: The word "computer" would take up how A motor which rotates at a fixed angle with many byte/s? any or all of its inputs are logic 1 each input pulse and its rotor is normally a 8 bytes fixed magnet with several poles and a Iron losses in a transformer are due to: stator with several windings. It is an interface between the CPU and the both eddy current and hysteresis losses Stepper motor memory (RAM and ROM), it helps the CPU keep running even though the RAM may be Shadowless light involves the principle of In a 74LS00 integrated circuit, "LS" means: too slow. Refraction Low power Schottky cache In a compound generator, which field Result obtained when a 1 is added to the The instructions used on a processor are winding usually, has a lower resistance? least significant bit position of a binary called series field winding number in the 7's-complement form. opcodes 8's-Complement Form Which winding in a dc-compound Mark that separates the integer from the generator that is relatively made of fine When you use an Op-Amp as a buffer fractional portion of a binary quantity. wires? circuit, the output voltage is: binary point shunt field winding Vout=Vin Video Graphics Adapter (VGA) is a What is the primary reason why carbon Typical specifications for a general standard which supports minimally brushes are preferred over copper brushes purpose integrated op-amp's output 640x480 with 16 colors in dc motors? impedance is: 75 ohms What do you call the amount of energy that they produce less arcing an electron needs before it can go to the In choosing a motor for a particular Average of the two input currents required conduction band? to drive the output voltage to zero. Energy gap application, what characteristic you should Input bias current consider? It is the monitored output variable from a speed-torque Electrical connection common to all process. segments of an LCD. Controlled or measured variable In applications where a high torque is Backplane needed during starting a ________ motor is It is the smallest amount of a variable that preferred. Maximum number of standard logic inputs an instrument can resolve or the smallest dc series that the output of a digital circuit can change in a variable to which the reliably drive. instrument will respond. In applications where an almost constant Fan-Out offset speed is required, a ______ motor is a good choice. Momentary, narrow, spurious, and sharply Materials that liberate electrons in the dc shunt defined change in voltage. presence of light. glitch Photoemissive cells When an armature opens in dc motor, it Program, stored in ROM, that a computer The closed-loop voltage gain of an inverting may cause executes on power-up. amplifier equals intermittent sparking bootstrap The feedback resistance divided by the input resistance The energy in a cell or battery depends mainly on: Its physical size Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 The type of crystal lattice in silicon and The amount of voltage needed at the gate- A T flip-flop is used primarily for which of germanium. source terminal for an enhancement type the following functions? face centered cubic (fcc) MOSFET so that a channel can be formed To divide the input frequency by two for the current to flow. The energy gap between the valence band Line regulation is determined by threshold voltage and conduction band of a semiconductor changes in output voltage and input is in the order of voltage The process of growing thin oxide film on one electron volt (1 eV) the surface of a planar semiconductor Load regulation is determined by device to protect the exposed junction(s) Typical range of the resistivity of a changes in load current & output voltage from contamination and shorts. semiconductor. passivation In a differentiator, the feedback element is 10 - 104 Ω-cm a ______. If the base-emitter junction is reverse resistor Chemical bond that is significant in biased and the base-collector junction is metals. forward biased, the transistor will be at Wien-bridge oscillators are based on metallic bonding what region of operation? positive feedback cut-off region What do you call a semiconductor that is Another name for memory is doped with both donor and acceptor Hybrid parameter that is usually neglected primary storage impurities? in most circuit analysis. compensated semiconductor hr and ho Printers and screens are common forms of output units Current flow in a semiconductor that is due GaAs is a(n): to the applied electric field. Compound The period of an ac wave is: drift current Equal to 1 divided by the frequency A CMOS integrated circuit: The movement of charge carriers in a Is susceptible to damage by static Magnetic flux can always be attributed to: semiconductor even without the Motion of charged particles application of electric potential. A semiconductor material is made into N type by: The useful current that is delivered by a diffusion current solar panel can be increased by: Adding a donor impurity Connecting two or more groups of solar For high-speed integrated circuit, which cells in parallel Holes flow the opposite way from electrons semiconductor material given below is because: best to be used? Charge carriers are passed from atom to An advantage of a rheostat over a gallium arsenide atom potentiometer is that: a rheostat can handle more current How much impurity concentration is What three-terminal IC regulator that has a needed for a sample of silicon to change variable negative voltage output? The force between two electrically charged its electrical property from a poor 337 objects is called: conductor to a good conductor? Electrostatic force one part per million Active devices used in switching regulators The capacitance between the primary and may experience large over-currents during the secondary windings of a transformer Semiconductor that has the highest heat conduction (turn-on-state) and large over- can be minimized by: conductivity and therefore used as a heat voltages during turn-off. These excessive Placing the windings on opposite sides of a sink. currents and voltages may cause toroidal core diamond distraction or damage of the active devices. How do we protect them? Who invented the battery? The voltage across the gate-source by installing a snubber circuit Alessandro Volta terminal of a FET that causes drain current ID equals to zero. In a complex control system, what For what is Charles Babbage (1792-1871) pinch-off voltage postulate the necessary compensating remembered? networks and cross-coupling networks and Computers What is the insulator used in most MOS- set their time constants? FET? compensating network Who invented Electric Generator? Michael Faraday SiO2 The simplest converter used in motor phase control. In which decade was the transistor Base from Shockley's equation of a JFET , half-wave converter invented? what is the drain current when the applied 1940s voltage VGS is exactly equal to the pinch-off What term is used to indicate current gain voltage VP? in a common-collector configuration? Who invented Bakelite? zero Gamma Leo Hendrik Baekeland Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 Who invented the phonograph? In which year was MIDI introduced? βdc for this set of collector characteristics John Kruesi 1983 is within _____ percent of βac. Who invented fuel cells in 1839? In which decade was the Internet first Sir William Grove implemented? 1960s The electric battery, who's charged with inventing this one? What did cardiologist Dr. Paul Zoll invent in Volta Massachusetts in 1952? Pacemaker In which decade was the first solid state integrated circuit demonstrated? What Elmer A. Sperry invented? 1950s Gyrocompass Ans. 10 Which scientist discovered the radioactive What type of system did Paul Nipkow, John βdc = ________ element radium? Baird, and Charles Jenkins all invent? Ans. IC / IB Marie Curie Television Who discovered the relationship between In which decade was the telephone What Sir Isaac Newton invented? magnetism and electricity that serves as invented? Reflecting telescope the foundation for the theory of 1870s electromagnetism? In which decade with the first transatlantic Hans Christian Oersted What now-ubiquitous device was invented radio broadcast occur? by Zenith engineer Eugene Polley in 1955? 1900s Who demonstrated the theory of Remote control electromagnetic induction in 1831? Use this table of collector characteristics Michael Faraday Who invented Gramophone? to calculate βac at VCE = 15 V and IB = 30 μA. Thomas Alva Edison Who developed the electromagnetic theory of light in 1862? In which decade were the first successful James Clerk Maxwell diode and triode vacuum tubes invented? 1900s Who discovered that a current-carrying conductor would move when placed in a Who is the English physicist responsible for magnetic field? the 'Big Bang Theory'? Michael Faraday George Gamow Who discovered the most important What invention is credited to the Russian Ans. 100 electrical effects which is the magnetic born American inventor Vladimir Kosma effect? Zworykin? Which of the following configurations can a Hans Christian Oersted Television transistor set up? A. Common-base Who demonstrated that there are magnetic What Thomas Davenport invented? B. Common-emitter effects around every current-carrying Electric streetcar C. Common-collector conductor and that current-carrying D. All of the above (Ans.) conductors can attract and repel each In which decade was the telegraph other just like magnets? invented? Determine the value of α when β= 100. Andre Ampere 1840s Ans. 0.99 Who discovered superconductivity in What invention was first installed at a Calculate βdc at VCE = 15 V and IB = 30 μA. 1911? Hartford, Connecticut bank in 1889? Kamerlingh Onnes Pay telephone What is part of a database that holds only When were bar code scanners invented? one type of information? 1970s Field This English inventor is known as the http://www.excelreviewcenter.com - is an 'Father of Computing.' example of what? Charles Babbage A URL In which decade was the SPICE simulator Which of the following is not a valid domain introduced? Ans. 110 name? 1970s A. www.yahoo.com What is the most frequently encountered B. www.yahoo.co.uk transistor configuration? C. www.fr.yahoo (Ans.) Ans. Common-emitter D. www.yahoo.fr Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 On which of the following sites can you set Who developed Yahoo? Which of these is not a computer? up your email account: David Filo & Jerry Yang A. Aptiva C Macintosh A. www.linux.org B Acorn D. Paseo (Ans.) B. www.gre.org Who built the world's first binary digit C. www.syvum.com computer: Z1...? Which of the following is not a D. www.hotmail.com (Ans.) Konrad Zuse programming language? A. Basic C Java Which of these is a search engine? The first step to getting output from a laser B Turing (Ans.) D. C# A. FTP is to excite an active medium. What is this B. Google (Ans.) process called? Which of the following is not a method of C. Archie Pumping accessing the web? D. ARPANET CPU Which motor is NOT suitable for use as a Which of these is a valid e-mail address? DC machine? The "home page" of a web site is... A. professor.at.learnthenet A. Permanent magnet motor The first page B. www.learnthenet.com B. Series motor C. [email protected] (Ans.) C. Squirrel cage motor (Ans.) HTML is used to... D. professor@learnthenet D. Synchronous motor Author webpages Google (www.google.com) is a... When measuring the characteristics of a When discussing technology, a hot spot is: Search Engine small-signal amplifier, say for a radio A place served by public wireless access receiver, one might be concerned with its '.MOV' extension refers usually to what "Noise _____". Lately you hear a clatter from your kind of file? Figure computer, especially when you load a Animation/movie file program or call up information. What's 'DB' computer abbreviation usually going on? '.MPG' extension refers usually to what means? Your hard disk may be headed for failure kind of file? Database Image file Which one of the following is a search '.INI' extension refers usually to what kind engine? '.TXT' extension refers usually to what kind of file? Google of file? System file Text File Which is the best search tool for finding Once the active medium is excited, the first Web sites that have been handpicked and '.TMP' extension refers usually to what kind photons of light are produced by which recommended by someone else? of file? physical process? Subject directories Temporary file Spontaneous emission What is a spider? '.JPG' extension refers usually to what kind A JPG is... A program that catalogs Web sites of file? A format for an image file Image file Which of the following is not a part of the Your computer has gradually slowed down. Internet? What was the first ARPANET message? What's the most likely cause? CD-ROM "lo" Adware/spyware is infecting your PC What is not always necessary for accessing '.BAK' extension refers usually to what kind Which was an early mainframe computer? the Web? of file? ENIAC A modem Backup file Experts say the healthiest way to view a A computer virus that actively attacks an '.BAT' extension refers usually to what kind computer monitor is by... anti-virus program or programs in an effort of file? Placing it 18 to 30 inches away from your to prevent detection is... System file eyes Retrovirus What is a web browser? What are the three main search Which of the following word processors A software program that allows you to expressions, or operators, recognized by came first? access sites on the World Wide Web Boolean logic? WordStar AND, OR, NOT Which is a type of Electrically-Erasable The invention of the transistor, or Programmable Read-Only Memory? Another name for a computer chip is... semiconductor, was one of the most Flash Micro chip important developments leading to the personal computer revolution. What The purpose of choke in tube light is? "www" stands for... company invented the transistor in 1947? To increase the voltage momentarily World Wide Web Bell Laboratories Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 What does PPTP stand for? In 1990, he wrote the Hypertext Transfer D. All of the above. Point to Point Tunneling Protocol Protocol (HTTP). Created the World Wide Web What must be done to interface CMOS to What is the World Wide Web? Tim Berners-Lee TTL? The part of the Internet that enables As long as the CMOS supply voltage is 5 V, information-sharing via interconnected Which of the following logic families has they can be interfaced; however, the fan- pages the highest maximum clock frequency? out of the CMOS is limited to two TTL gates. AS-TTL This virus activated every Friday the 13th, What is the static charge that can be affects both.EXE and.COM files and Which of the following logic families has stored by your body as you walk across a deletes any programs run on that day. the shortest propagation delay? carpet? What is the name of that virus? AS-TTL Over 30,000 volts Jerusalem Why is the fan-out of CMOS gates What type of circuit is represented in the A program that neither replicates or copies frequency dependent? given figure, and which statement best itself, but does damage or compromises The input gates of the FETs are describes its operation? the security of the computer. predominantly capacitive, and as the Trojan virus signal frequency increases the capacitive loading also increases, thereby limiting the Which Intel chip was the first to support a number of loads that may be attached to It is a tristate inverter. When the ENABLE 32-bit bus architecture? the output of the driving gate. input is HIGH, the output is effectively an 386DX open circuit—it is neither LOW nor HIGH. Logic circuits that are designated as The first graphical browser for the WWW buffers, drivers, or buffer/drivers are Which of the following logic families has was named: designed to have: the highest noise margin? Mosaic a greater current/voltage capability than an HCMOS ordinary logic circuit. What is RISC? Which of the logic families listed below Reduced Instruction Set Computer Which of the following will not normally be allows the highest operating frequency? found on a data sheet? ECL Which of these is a documented hoax Minimum LOW level output voltage B. virus? What type of logic circuit is shown below McDonalds screensaver Which of the following summarizes the and what logic function is being important features of ECL? performed? What is a URL? Low noise margin, low output voltage The address of a document or "page" on swing, negative voltage operation, fast, and the World Wide Web high power consumption The Central Processing Unit is an embeded What must be done to interface TTL to chip that acts as the 'brains' of a computer. CMOS? What Intel chip was used in the Altair (the A. A pull-up resistor must be used between first real personal computer)? the TTL output-CMOS input node and Vcc; 8080 the value of RP will depend on the number It is a CMOS NOR gate. of CMOS gates connected to the node. The Internet was developed in the... Whenever a totem-pole TTL output goes Late 1960s What causes low-power Schottky TTL to from LOW to HIGH, a high-amplitude use less power than the 74XX series TTL? current spike is drawn from the Vcc supply. Sometimes called the "father of the A larger value resistor How is this effect corrected to a digital ARPANET." circuit? Larry Roberts What are the major differences between By connecting a radio-frequency capacitor the 5400 and 7400 series of ICs? from Vcc to ground. Invented the computer mouse. A. The 5400 series are military grade and Douglas Engelbart allow for a wider range of supply voltages What type of circuit is shown below and and temperatures. which statement best describes its Developed the Ethernet C. operation? Bob Metcalfe Which of the following statements apply to CMOS devices? Father of the Internet A. The devices should not be inserted into Vinton Cerf circuits with the power on. B. All tools, test equipment, and metal Coined the term “hypertext” workbenches should be tied to earth Ted Nelson ground. It is a CMOS inverter with tristate output. C. The devices should be stored and A "floating" TTL input may be defined as: shipped in antistatic tubes or conductive Fan-out for a typical TTL gate is ________. unused input that is not connected. foam. 10 Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 What is the increase in switching speed What output levels would not be a valid An open-collector TTL gate ________. between 74LS series TTL and 74HC/HCT LOW for a TTL gate? can sink current but cannot source current (High-Speed CMOS)? A. 0.2 V C. 0.3 V 10 B. 0.5 V D. All of the above. One advantage that MOSFET transistors have over bipolar transistors is ________. A logic signal experiences a delay in going The propagation delay of standard TTL high input impedance through a circuit. The two propagation gates is approximately ________. delay times are defined as: 10 ns The time it takes for an input signal to pass tPLH and tPHL through internal circuitry and generate the Several manufacturers have developed appropriate output effect is known as What does ECL stand for? logic that combines the best features of ______. It stands for emitter-coupled logic; all of TTL and CMOS. This is called ________. propagation delay the emitters of the input transistors are BiCMOS connected together and each transistor The 74F-Fast TTL integrated-circuit functions as an emitter follower. Totem-pole outputs ________ be connected fabrication technique uses reduced ________ because ________. inter-device ________ to achieve reduced What is unique about TTL devices such as cannot, together, if the outputs are in propagation delays. the 74S00? opposite states excessively high currents capacitance The devices use Schottky transistors and can damage one or both of the devices diodes to prevent them from going into In a DIP the spacing between pins is saturation; this results in faster turn on and The power dissipation of a CMOS IC will __. typically ________. turn off times, which translates into higher increase with frequency 100 mils frequency operation. When VGS = 0 on an N-channel MOSFET Which is about twice as fast as P-MOS? Generally, the voltage measured at an switch, there is no ________ between the A. N-MOS unused TTL input would typically be source and the drain. measured between: conductive channel P-MOS and N-MOS ________. 1.4 to 1.8 V. represent MOSFET devices utilizing either The number of gates that can be P-channel or N-channel devices The IEEE/ANSI notation of an internal connected to a single output without exclusively within a given gate underlined diamond denotes: exceeding the current ratings of the gate is open-collector outputs. called ______. The output stage of a TTL gate is a special fan-out design called ________. Refer to the figure given below. What type totem-pole of device is shown and what input levels The output current for a LOW output is are required to turn the LED off? called a(n) ________. The ________ is defined as the maximum sink current number of standard logic inputs that an output can drive reliably. What TTL allows three possible output fan-out states? Tristate What is ideally suited for applications using battery power or battery backup The device is an open-collector AND gate The proliferation of small handheld power? and requires both inputs to be HIGH in consumer equipment such as digital video A. CMOS order to turn the LED off. cameras, cellular phones, handheld computers (________), portable audio A logic probe is placed on the output of a The bipolar TTL logic family that was systems, and other devices have created a digital circuit and the probe lamp is dimly developed to increase switching speed by need for logic circuits in very small lit. This display indicates ________. preventing transistor saturation is: packages. that an open or bad logic level exists transistor logic (TTL). PDAs A logic probe is placed on the input of a When the outputs of several open-collector The lower transistor of a totem-pole output digital circuit and the probe lamp blinks TTL gates are connected together, the gate is saturated when the gate output is ______. slowly, indicating ________. outputs ________. LOW a high-frequency pulse train are ANDed together When the output of a standard TTL gate is The HIGH logic level for a standard TTL The minimum input voltage recognized as HIGH, it can ________. output must be at least ________. HIGH by a TTL gate is ________. source 400 uA of current to no more than 2.4 V 2.0 V 10 attached gates In case of class A amplifiers, the ratio of Propagation delay is important because A ________ is a testing and troubleshooting efficiency of transformer coupled amplifier ________. tool that generates a short-duration pulse to efficiency of a transformer less amplifier the logic gates must be given a short break when manually activated, usually by is during each clock cycle or else they will depressing a push button. 2.0 overheat logic pulser Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 In a transistor push-pull amplifier The type of single-phase induction motor External quantum efficiency is the optical there are no even harmonics in the output having the highest power factor at full load power emitted from a light emitting device is ______. per unit ______. A single phase full-wave half-controlled capacitor-run type Electric input power bridge converter feeds an inductive load. The two SCRs in the converter are What semiconductor contains both donors It is a junction between different connected to a common DC bus. The and acceptors in the same crystal region semiconductor materials, for example, converter has to have a freewheeling that compensate for each other’s effects? between GaAs and AlGaAs ternary alloy. diode: Compensated semiconductor Heterojunction because the converter does not provide for free-wheeling for high values of triggering What is the energy required to remove an It is a junction between differently doped angles electron from conduction band edge to the regions of the same semiconducting vacuum level? materials, for example, a pn junction in the “Six MOSFETs connected in a bridge Electron affinity same silicon crystal. configuration (having no other power Homojunction device) must be operated as a Voltage Which of the following semiconductor that Source Inverter (VSI)”. This statement is: has so many dopants that the electron What will occur when an applied voltage to False, because MOSFETs can be operated concentration in the conduction band, or the gate of a metal oxide semiconductor as excellent constant current sources in hole concentration in the valence band, is device causes the semiconductor under the saturation region. comparable with the density of states in the oxide to develop a conducting layer or a the band? channel at the surface of the Transformer and emitter follower can both Degenerate semiconductor semiconductor? be used for impedance matching at the Inversion output of an audio amplifier. The basic What semiconductor that has electrons in relationship between the input power Pin the conduction band and holes in the In solar cell, what figure of merit for a solar and output power Pout in both the cases is: valence band that obey Boltzmann cell that represents the maximum power Pin = Pout for transformer and Pin < Pout for statistics. available to an external load as a fraction emitter follower Non-degenerate semiconductor of the ideal theoretical power determined by the product of the short circuit current In an 8085 A microprocessor based In semiconductor, minority carrier and the open circuit voltage? system, it is desired to increment the diffusion length, (L), is the mean distance a Fill factor contents of memory location whose minority carrier diffuses before address is available in (D,E) register pair recombination. Mathematically, L is equal What law that relates the injected minority and store the result in same location. The to the square root of the product of carrier concentration just outside the sequence of instruction is minority carrier lifetime and the ________. depletion layer to the applied voltage? INR M Diffusion coefficient Law of the junction XCHG It is a contact that can supply charge In semiconductor technology, it is a single The 8085 assembly language instruction carriers to a semiconductor at a rate mechanical support that carries active and that stores the content of H and L register determined by charge transport through passive devices. into the memory locations 2050H and the semiconductor and not by the contact Substrate 2051H, respectively is properties itself. SHLD 2050H Ohmic contact What is the phenomenon of heat absorption or liberation at the contact Synchronous generator is feeding a zero What energy required to remove an between two dissimilar materials as a power factor (lagging) load at rated electron from the solid to the vacuum result of a dc current passing through the current. The armature reaction is level? junction? demagnetizing Work function Peltier effect Which three-phase connection can be It will occur when an applied voltage to the What energy level corresponding to the used in a transformer to introduce a phase gate of a metal oxide semiconductor energy required removing an electron from difference of 30º between its output and (MOS) device causes the semiconductor the semiconductor? (there need not be any corresponding input line voltages under the oxide to have a greater number actual electrons at this energy) Star-Delta of majority carriers than the equilibrium Fermi level value. For a given stepper motor, the following Accumulation The semiconductor region near the torque has the highest numerical value junction in which there are excess Pull-out torque In semiconductor devices, what field in the electrons is called space charge or depletion region at reverse Accumulation junction The following motor definitely has a breakdown? permanent magnet rotor Critical electric field In optical semiconductor, Beer-Lambert Stepper motor law states that the transmitted intensity What are the two basic types of JFET? decreases exponentially with the ______. How are junction diodes rated? N-channel and P-channel Thickness Maximum forward current and PIV Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 What is an enhancement-mode FET? Why is the resistance of a conductor Where is the external feedback network An FET without a channel, no current different for RF current than for DC? connected to control the gain of a closed- occurs with zero gate voltage Because of skin effect loop op-amp circuit? From output to inverting input When a semiconductor material An optical shaft encoder is an array of bombarded by high energy electron beam, optocouplers: What is the name of the random-accessed it is possible to excite electrons into the whose light transmission path is controlled semiconductor memory IC that must be conduction band and if these electrons by a rotating wheel refreshed periodically to maintain reliable recombine with holes and emits light, then data storage in its memory matrix? this process is called What is the principal characteristic of a DRAM Cathodoluminescence zener diode? A constant voltage under conditions of Which is not an advantage of using The excess energy is lost to lattice varying current pentode? vibrations as heat as the electron is Higher secondary emission resulting in scattered from one atomic vibration to What type of diode often used in RF greater plate current another. This process is called switches, attenuators, and various types of Thermalization phase shifting devices? Which is not an advantage of gaseous PIN diode tubes? To determine the carrier concentration at Carry relatively low current any point at any instant we need to solve What two elements widely used in _________, which is based on accounting semiconductor devices exhibits both A PLL IC could be used in all of the for the total charge at that location in the metallic and non-metallic characteristics? following EXCEPT: semiconductor. Silicon and germanium Phase-shift oscillator Continuity equation What is a crystal lattice filter? Which of the following is contained in an A _____ is quantum of energy associated A filter with narrow bandwidth and steep LCD display? with atomic vibrations in the crystal skirts made using quartz crystals. Nematic fluid analogous to the photon. Phonon What is one major advantage of CMOS over When referring to digital ICs, which one other devices? contains between 100 to 9999 gates? High-temperature range in semiconductor Low current consumption LSI is also known as intrinsic range, for medium-temperature range is also known What logic state do the inputs of a TTL Which of the following is NOT an analog to as extrinsic range while low-temperature device assume if they are left open? digital converter? range is known as ______. A high logic state R/2R ladder ADC Ionization range A circuit compares the output from a What probable effect on the human body if What is the maximum frequency of lattice voltage-controlled oscillator and a subjected to a current of 1 to 4 mA, 60 Hz, vibrations that can exist in a crystal? frequency standard. The difference AC or 4 – 15 mA, DC? Debye frequency between the two frequencies produces an Surprise error voltage that changes the voltage- It is a wave in crystal due to coupled controlled oscillator frequency. What is Which device is normally used to regulate oscillations of the atom. It may be this circuit called? the amount of ac current flowing to a load travelling or stationary waves. Phase-locked loop from approximately 0 degrees to no more Lattice wave than 180 degrees of the input signal? Most bipolar junction transistors have a SCR _____ is the application of a temporary ______ doped and _____ collector region electric field to a piezoelectric material, compared to the base and emitter regions. Which of the following devices is used generally at an elevated temperature, to medium, large principally as VHF and UHF parasitic align the polarizations of various grains and suppressers? thereby develop piezoelectric behavior. What describes a diode junction that is Ferrite bead Poling forward biased? It is a low impedance What limits the maximum forward current What is a semiconductor device structure in a junction diode? that has junctions between different What semiconductor device controls Junction temperature bandgap materials? current between source and drain due to a Heterostructure device variable width channel controlled by a What does it mean for a transistor to be cut voltage applied between gate and source? off? The phenomenon of light emission from FET emitter and collector electron-hole pair recombination as a result of minority carrier injection is called The capacitance of a varactor ______ as the What is the opposition to the creation of Injection electroluminescence _____ bias is increased. Assume proper magnetic lines of force in a magnetic bias to use the diode as a varactor. circuit? What are the advantages of using an LED? decreases, reverse Reluctance Low power consumption and long life. Website: www.excelreviewcenter.com.ph Facebook: Excel Review Center Cellphones: Smart: 0919 822 5048 Globe: 09173239235  EXCEL FIRST REVIEW AND TRAINING CENTER, INC. Cebu: JRT Bldg. Imus Ave, Cebu City | Manila: CMFFI Bldg. R. Papa St. Sampaloc Electronics Engineering Baguio: 4th Fl. De Guzman Bldg., Legarda Road | SPLE: GCC and Singapore Review Materials Q & A 1 Halving the cross-sectional area of a The leads to the primary and to the high- A transformer used in a radio-frequency conductor will: voltage secondary windings of a power circuit to transfer rf signal from one circuit double the resistance transformer usually are of what color? to another. Primary leads – BLACK , Secondary leads – Radio-frequency transformer What turn ratio does a transformer need to RED match a source impedance of 500 ohms to The distance, usually, expressed in meters, a load of 10 ohms? What probable effect on the human body if traveled by a wave during the time interval 7.1 to 1 subjected to a current of 0 to 1 mA, 60 Hz, of one complete cycle. AC or 0 to 4 mA DC? Wavelength What is the average fully charged voltage of Perception an Edison storage cell? A transformer so constructed that the 1.2 volts What probable effect on the human body if number of turns in the secondary winding subjected to a current of 4 to 21 mA, 60 Hz, is more than the number of turns in the The product of the readings of an ac AC or 15 to 80 mA, DC? primary winding? voltmeter and ac ammeter is called _____. Reflex action Step-up transformer apparent power What probable effect on the human body if A transformer so constructed that the What is the purpose of a multiplier resistor subjected to a current of 21 to 40 mA, 60 number of turns in the secondary winding used with a voltmeter? Hz, AC or 80 to 160 mA, DC? is less than the number of turns in the It is used to increase the voltage indicating Mascular inhibition primary winding. range of voltmeter Step-down transformer What probable effect on the human body if What is responsible for the phenomenon subjected to a current of 40 to 100 mA, 60 The ratio of output power to input power, when voltages across reactances in series Hz, AC or 160 to 300 mA, DC? generally expressed as a percentage. can often be larger than the voltage applied Respiratory failure Transformer efficiency to them? Resonance What probable effect on the human body if When light shines on a photoconductive subjected to a current of over 100 mA, 60 material, its conductivity will ______. What is the approximate magnitude of the Hz, AC or 300 mA, DC? increase impedance of a series R-L-C circuit at Fatal resonance? The expression “voltage regulation” as it Approximately equal to the circuit What refers to the jarring, shaking applies to a generator operating at a resistance sensation you receive from contact with constant frequency refers to: electricity? full load to no load In what direction is the magnetic field Electric shock about a conductor when current is flowing? The gain of a theoretically ideal operational In a direction determined by the left-hand Before working on electrical equipment amplifier is _____ with increasing rule containing capacitors, what should you do frequency. to the capacitor? does not vary What refers to the lines of flux generated by Discharge them by shorting them to ground one winding which do not link with the What is the purpose of a bypass capacitor? other winding? The ______ of a transformer is the ratio of Blocks dc and passes ac leakage flux the number of turns of wire in the primary winding to the number of turns in the For a circuit to oscillate, it must What effect does flux leakage in a secondary winding. have positive feedback sufficient to transformer have on the coefficient of turn ratio overcome losses coupling (k) in the transformer? It causes k to be less than unity. A perfect transformer would have an What is the function of a decade counter efficiency of _____. digital IC? Power transformer normally operates at 1 or 100 % Produce one output pulse for every ten _____ alternating current. input pulses 60 Hz or 400 Hz A transformer with a single winding in