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Energy Conversion

357 questions · page 18 of 18. Answer in your head first, then check the solution.

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#341
A three terminal variable positive voltage regulator
A317
B337
C723
D741
#342
What three-terminal IC regulator that has a variable negative voltage output?
A317
B337
C723
D741
#343
In a three-terminal adjustable positive voltage regulator 317, what is the band-gap votage between the output terminal and adjustment terminal?
A1.25 V
B2.5 V
C3.25 V
D4.125 V
#344
Typical ripple rejection of most three-terminal voltage regulators
A0.1 %
B0.8 %
C1.2 %
D2.0 %
#345
The 3terminal voltage regulators, such as the 78XX series has a typical current rating of 1.5 amperes. If a high current is required, say 30A, how will you make modifications from this regulator in order to provide the required current?
Aby cascading them
Bby the use of a crowbar circuit
Cby connecting them in parallel
Dby the use of external pass transistor
#346
What is the simplest way of protecting power supplies from reverse-polarity / reverse-current flow?
Aby a forward-biased diode
Bby a reverse-biased diode
Cby a crowbar circuit
Dby a snubber circuit
#347
A crowbar circuit is used
Ato monitor the output current of a power supply and automatically shuts down the system when an overload occur
Bto monitor the temperature of a power supply and switches the cooling fan when a treshold temperature is reached
Cas voltage reference in regulated power supplies
Das an over-voltage protection in power supplies
#348
Technique in using low-power, low-voltage transistors in high voltage regulators
Aground return regulation
Bby lifting the regulator above ground
Cconnecting them in series
Dall of them
#349
Which of the regulators dissipates less power and therefore generates less heat?
Aseries
Bshunt
Cswitching
DUPS
#350
In switching regulators, what are the semiconductor devices that can be used as controllable power switches?
ABJTs and MDs
BMOSFETs and IGBT
CGTOs and thyristors
Dall of them
#351
What are the desirable characteristics of the control element to be used if excellent regulator is desired?
Avery small off-state leakage current and high on-state current ratings
Blarge forward and reverse blocking voltage and very small on-state voltage
Cshort turn-on and turn-off times so that it can be used in high-speed switching regulators
Dall of them
#352
Active devices used in switching regulators may experience large currents during conduction and large over-voltages during turn-off. These excessive currents and voltages may cause distraction or damage of the active devices. How do we protect them?
Aby the use of a crowbar circuit
Bby providing a buck-boost circuit
Cby shunting a thyrector
Dby installing a snubber circuit
#353
What circuit is used to clean up or shape up the utility supply voltage from overvolt, undervolt, voltage spikes, and harmonic distortions?
Apower conditioners
BUPS
Cpower inverters
Dline scanning
#354
A power supply that continously provides against undervoltage, overvoltage and even power outages
Astandby power supply
Buninterruptible power supply
Cpower conditioners
Dregulated power supply
#355
Which of the following is not a secondary cell?
ASilver-Zinc
BNickel-Iron
CSilver-Oxide
DLead-Acid
#356
Which of the following is not a primary cell?
ACarbon-zinc
BZinc chloride
CEdison cell
DMercuric acid
#357
The greatest percentage of heat/power loss in a dc motor is due to
Awindage loss
Bcore loss
Ccopper loss
Dfriction loss

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