Description : On AC vessels, which of the following statements represents the most difficult problem involved in obtaining a DC potential suitable for use by computer components? A. A stepdown transformer is ... voltage must be rectified and made ripple free. D. Rectifiers cannot operate with voltage regulators.
Last Answer : Answer: C
Description : RC time constant characteristics, as shown in the illustration, are important in _____________. EL-0086 A. bridge rectifiers for alternator excitation B. timing and pulse shaping circuits C. transistor power amplifier biasing D. motor controller overload protection
Last Answer : Answer: B
Description : High vacuum diodes, gas-filled diodes, and germanium semiconductor diodes may all be used as _____________. A. potentiometers B. rectifiers C. power sources D. photocells
Description : Rectifiers are used to convert - (1) Direct current to Alternating current (2) Alternating current to Direct current (3) high voltage to low voltage (4) low voltage to high voltage
Last Answer : (2) Alternating current to Direct current Explanation: Converting DC power from one voltage to another is much more complicated. One method of DC-to-DC conversion first converts power to AC (using a ... inverter), then uses a transformer to change the voltage, and finally rectifies power back to DC.
Description : What is the PIV of all type rectifiers?
Last Answer : The PIV of rectifier: - Half wave rectifier=Vm, Center tape wave rectifier=2Vm Bridge full wave=Vm
Description : ECE Board Exam March 1996 A device to be connected across the headset in telephone receivers to reduce the effects of acoustic shock. A. Ground B. Two rectifiers in parallel with opposite polarities C. Protector D. Fuse
Last Answer : B. Two rectifiers in parallel with opposite polarities
Description : A half-wave voltage doubler is made up of how many half wave rectifiers?
Last Answer : Two.
Description : State classification of Phase controlled rectifiers.
Last Answer : Classification of phase controlled rectifiers:
Description : A freewheeling diode in phase -controlled rectifiers (a) enables inverter operation (b) is responsible for additional reactive power (c) improves the line power factor (d) is responsible for additional harmonics
Last Answer : A freewheeling diode in phase -controlled rectifiers improves the line power factor
Description : Electronic Voltmeters which use rectifiers employ negative feedback. This is done - a) To increase the overall gain b) To improve stability c) To overcome non -linearity of the diodes d) None of the above
Last Answer : Electronic Voltmeters which use rectifiers employ negative feedback. This is done - To overcome non -linearity of the diodes
Last Answer : Ac to dc
Description : As shown in the illustration, the generator field is excited with DC current provided by ____________. EL-0016 A. conductors '1', '2' and '3' B. inductor 'L1' C. rectifier 'CR1' D. winding 'S-2'
Description : Unnecessary and frequent applications of varnish to the generator windings to repair defective insulation will result in ____________. A. heavy coatings of varnish interfering with heat dissipation B. ... of the rectifier assembly D. a built-up of varnish without changing generator operation
Last Answer : Answer: A
Description : The illustrated device is a _______. EL-0064 A. full wave bridge rectifier B. half wave bridge rectifier C. solid state voltage regulator D. direct current (DC) filter
Description : The correct term for the illustrated circuit is a ________. EL-0063 A. single phase half wave high power rectifier B. three phase half wave rectifier C. three phase full wave rectifier D. a single phase full wave rectifier
Description : A device used in an electrical circuit to change alternating current to direct current, is known as a _____________. A. current transformer B. rectifier C. condenser D. shunt
Description : What does the arrangement at coordinates '62E' shown in the illustration represent? EL-0099 A. Position recording drum and stylus B. Temperature compensating thyristor C. Miniature bridge rectifier D. Twisted wire pair within a shield
Last Answer : Answer: D
Description : What can be used to replace the exciter in the circuit shown in the illustration? EL-0101 A. A step-up transformer. B. A rectifier. C. A step-down transformer. D. An operational amplifier.
Description : The schematic diagram shown in the illustration represents which of the listed solid-state circuits? EL-0069 A. Bridge rectifier B. Magnetic amplifier C. Flip-flop generator D. Cathodic amplifier
Description : Component 'B' of section 'I' shown in the illustration represents a _____________. EL-0093 A. bridge rectifier B. selsyn motor C. small generator D. shielded lamp
Description : One diode of a full-wave rectifier has burned out in a shorted condition. Therefore, the output will be ____________. A. zero B. a rectified half-wave C. a rectified full-wave D. equal to the AC input
Description : A full-wave rectifier has one diode burned out in an open condition, what will be the output characteristic of the device? A. Zero B. Half-wave rectified C. Full-wave rectified D. Equal to the AC input
Description : Section II of the circuit shown in the illustration is the ____________. EL-0085 A. voltage regulator B. filter C. rectifier D. voltage transformer
Description : Section IV of the circuit shown in the illustration is the _____________. EL-0085 A. voltage regulator B. filter C. rectifier D. voltage transformer
Description : Basically, a magnetic amplifier is a saturable reactor with the addition of _____________. A. AC to the bias winding B. variable capacitance to all windings C. eddy current protectors D. a rectifier in the load circuit
Description : Section III of the circuit shown in the illustration is a _____________. EL-0085 A. voltage regulator B. filter C. rectifier D. voltage transformer
Description : In the illustrated circuit, section II is considered to be a _______. EL-0085 A. full wave rectifier B. half wave rectifier C. quarter wave rectifier D. short wave rectifier
Description : Which of the following expresses the relationship of the input and output frequencies in a full wave rectifier? A. The output frequency is the same as input frequency. B. The output frequency is ... frequency is twice the input frequency. D. The output frequency is four times the input frequency.
Description : The function of a rectifier is similar to that of a _______. A. trap B. regulating valve C. check valve D. filter
Description : A silicon controlled rectifier (SCR) is a solid state device used to change ________________. A. DC to AC and control relatively low load current B. AC to DC and control relatively high load ... to AC and control relatively high load current D. AC to DC and control relatively low load current
Description : Figure 'B' shown in the illustration represents a/an ____________. EL-0067 A. silicon controlled rectifier B. junction field effect transistor C. diac thyristor D. IG MOS field effect transistor
Description : Due to its construction, the component in figure 'A' shown in the illustration has which of the listed advantages compared to bipolar devices? EL-0078 A. Operates with higher voltages and ... as a controllable rectifier. D. Has very high input resistance and uses practically no gate current.
Description : Figure 'C' shown in the illustration represents a _________. EL-0078 A. silicon controlled rectifier B. light emitting diode C. photosensitive diode D. Zener diode
Description : Since the characteristics of the device shown in figure 'A' of the illustration includes a stable voltage and low current while operating, it can be suitably used in _____________. EL-0065 A. oscillators ... . class A and B amplifiers C. generator rectifier and filtering supplies D. all of the above
Description : Which of the following statements represents the important factor that must be considered when replacing a faulty diode in the exciter rectifier assembly? A. Be certain that the replacement diode ... The replacement diode must be dipped in varnish prior to installation to protect against humidity.
Description : The most common source of excitation for synchronous motors is a/an ______________. A. stepup transformer B. half-wave rectifier C. DC supply D. AC supply
Description : Figure 'A' of the diagram shown in the illustration represents a/an ____________. EL-0078 A. silicon controlled rectifier B. IG or MOS field effect transistor C. triac thyristor D. junction field effect transistor
Description : Figure 'D' shown in the illustration represents a _________. EL-0067 A. silicon controlled rectifier B. light emitting diode C. photosensitive diode D. Zener diode
Description : Figure 'B' of the diagram shown in the illustration represents a/an ____________. EL-0065 A. silicon controlled rectifier B. junction field effect transistor C. diac thyristor D. IG or MOS field effect transistor
Description : The symbol in figure 'A' shown in the illustration represents a ____________. EL-0065 A. diac B. field effect transistor C. silicon controlled rectifier D. unijunction transistor
Description : Heat sinks are frequently used with _____________. A. power transistors B. vacuum tubes C. tunnel rectifier diodes D. all of the above
Description : Which of the listed devices is used to measure pressure and convert it to an electrical signal? A. Transducer B. Reducer C. Transformer D. Rectifier
Description : The use of four diodes, in a full-wave bridge rectifier circuit, will __________. A. provide unidirectional current to the load B. allow a very high leakage current from the load C. convert direct current to alternating current D. offer high opposition to current in two directions
Description : Which of the following statements represents an application of a silicon controlled rectifier? A. To provide DC power for a main propulsion motor. B. For use as a voltage reference diode. C. For sensing flame in an automated burner. D. To eliminate power supply hum.
Description : What are the advantages of freewheeling diodes in a controlled in a controlled rectifier?
Last Answer : a. Input power factor is improved. b. Load current waveform is improved and thus the load performance is better.
Description : What is the function of freewheeling diodes in controlled rectifier?
Last Answer : It serves two process. a. It prevents the output voltage from becoming negative. b. The load current is transferred from the main thyristors to the freewheeling diode, thereby allowing all of its thyristors to regain their blocking states.
Description : Mention some of the applications of controlled rectifier.
Last Answer : a. Steel rolling mills, printing press, textile mills and paper mills employing dc motor drives. b. DC traction c. Electro chemical and electro-metallurgical process d. Portable hand tool drives e. Magnet power supplies f. HVDC transmission system
Description : What is meant by phase controlled rectifier?
Last Answer : It converts fixed ac voltage into variable dc voltage.
Description : What is delay angle or what is firing angle of phase controlled rectifier?
Last Answer : The delay angle is the angle at which thyristors are triggered after zero crossing. After zero crossing of supply voltage, one pair of thyristors is forward biased. After delay angle(α) these SCRs are triggered.