To get minimum harmonic distortion in the output, a 3-Ф to 3-Ф cyclo-converter requires : 36 SCRs
Description : The second harmonic distortion is defined as the A) Ratio of amplitude of second harmonic component in the output to that of the fundamental frequency B) Harmonic distortion due to only second harmonic component C) Sum of distortion of first and second harmonic components in the output
Last Answer : The second harmonic distortion is defined as the Ratio of amplitude of second harmonic component in the output to that of the fundamental frequency
Description : Explain the sinusoidal harmonic reduction techniques for cylcoconverters.
Last Answer : sinusoidal
Description : The time period of third harmonic of power supply frequency, in milliseconds, is (A) 20 (B) 3.33 (C) 6.66 (D) 60
Last Answer : The time period of third harmonic of power supply frequency, in milliseconds, is 6.66
Description : The fractional-pitch used for eliminating 7th harmonic from the emf wave of an alternator is (A) 2/3 (B) 5/6 (C) 7/8 (D) 6/7
Last Answer : The fractional-pitch used for eliminating 7th harmonic from the emf wave of an alternator is 6/7
Description : What is the harmonic filter?
Last Answer : It is being used to supress the input voltage distortion at input side of any electrical equipment. This distortion is created by other electrical loads like motor, drives etc nearby connected with ... for a range of harmonics or specific harmonics like 3rd harmonics 5th harmonics, 7th harmonics.
Description : What are the applications of cyclo-converter?
Last Answer : a. Induction heating b. Speed control of high power ac drives c. Static VAR generation d. Power supply in aircraft or ship boards
Description : What is meant by cyclo-converter?
Last Answer : It converts input power at one frequency to output power at another frequency with one-stage conversion. Cycloconverter is also known as frequency changer.
Description : What is step up cyclo-converter ?
Last Answer : It is the converter whose output frequency is more than the input frequency.
Description : What is step down cyclo-converter?
Last Answer : It is the converter whose output frequency is less than the input frequency.
Last Answer : It is also known as frequency changer. It converts input power at one frequency to output power at another frequency with one stage conversion.
Description : Draw single phase full wave mid-point converter for inductive load. Draw input and output waveforms for it.
Last Answer : Circuit Diagram: Waveforms:
Description : Which distortion is least objectionable in case of audio amplifers? A) Phase distortion B) Frequency distortion C) Harmonic distortion D) Inter modulation distortion.
Last Answer : A) Phase distortion
Description : When measuring harmonic distortion, you set the signal generator to input a 15-kHz test signal. To what frequency should you set the wave analyzer?
Last Answer : 45 kHz.
Description : What number harmonic is the primary harmonic distortion in magnetic tape recorders?
Last Answer : Third-order harmonic.
Description : A recorder’s harmonic-distortion specification reads 2% third harmonic of a 100-kHz signal at 60 ips. What does this mean?
Last Answer : The recorder has 2% third-harmonic distortion of a 100-kHz signal at 60 ips.
Description : ___ has a series RC combination in one arm and a parallel RC combination in the adjoining arm and used as a notch filter in harmonic distortion analyzer.
Last Answer : wein bridge
Description : What is the effect of following on induction motors: (1) Voltage unbalance (2) Harmonic distortion
Last Answer : i) Effect of voltage unbalance: For three phase motors this leads to unequal currents in the three phase windings that result in unbalance in the fields produced due to which negative phase ... currents thereon). This leads to motor failures, lower life and improper torque speed characteristics.
Description : Harmonic distortion of the signal is produced in an RC coupled transistor amplifier. The probable component responsible for this distortion is (A) The transistor itself (B) the power supply Vcc (C) the coupling capacitor Cc (D) the biasing resistors
Last Answer : Harmonic distortion of the signal is produced in an RC coupled transistor amplifier. The probable component responsible for this distortion is The transistor itself
Last Answer : Harmonic distortion is due to Non-linear behaviour of circuit elements
Description : In single pulse modulation of PWM inverters, third harmonic can be eliminated if pulse width is equal to (a) 30o (b) 60o (c) 120o (d) 150o
Last Answer : In single pulse modulation of PWM inverters, third harmonic can be eliminated if pulse width is equal to 120o
Description : An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is (1) 141 (2) 92.3 (3) 9.23 (4) 1.41
Last Answer : An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is 9.23
Description : Draw circuit diagram of symmetrical configuration of bridge converter.
Last Answer : circuit diagram of symmetrical configuration of bridge converter
Description : Give the operation of single phase full wave bridge controlled converter with RL load with a neat diagram. Also draw its waveform.
Last Answer : Single phase fully control bridge converter with RL load: 1. During positive half cycle of input voltage, T1 and T2 are forward biased and during negative half cycle, T3 and T4 are forward biased. Therefore, T1-T2 ... cycle till the firing of next pair of SCRs as shown in the waveform.
Description : Give the effect of source impedance on converter operation.
Last Answer : Effect of source impedance on converter operation: For single-phase fully controlled bridge converter, the SCRs are triggered in pairs alternately. During positive half-cycle of input, SCRs T1 and T2 are triggered ... increases and as a consequence, the output dc voltage decreases.
Description : Draw a neat diagram of 1Ф half wave controlled converter with RL load. Give its operation.
Last Answer : Single phase fully controlled half wave converter: The circuit diagram of single-phase half-wave controlled rectifier with RL load and without freewheeling diode is shown in Fig. (a). The SCR T is ... , when again pulse is applied, the SCR is turned on & the above cycle is repeated.
Description : A single phase fully controlled bridge converter supplies a load drawing constant and ripple free load current, if the triggering angle is 30o, the input power factor will be (A) 0.65 (B) 0.78 (C) 0.85 (D) 0.866
Last Answer : A single phase fully controlled bridge converter supplies a load drawing constant and ripple free load current, if the triggering angle is 30o, the input power factor will be 0.78
Description : In a single-phase full converter, the number of SCRs conducting during overlap is (a) 1 (b) 2 (c) 3 (d) 4
Last Answer : 4
Description : The percent resolution of an 8 -bit D/A converter is
Last Answer : The percent resolution of an 8 -bit D/A converter is 0.392
Description : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is
Last Answer : Please show the solution for this question
Description : A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is (A) 4.5 V (B) 6.75 V (C) 9 V (D) 13.5 V
Last Answer : A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is 9 V
Description : In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is (A) sinusoidal current (B) constant dc current (C) continuous rectangular pulses (D) alternating rectangular pulses
Last Answer : In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is alternating rectangular pulses
Description : Why the power factor of semiconverter is better than full converter?
Last Answer : Power factor of semiconverter is better than full converter
Description : Explain buck or step down converter and draw its waveforms.
Last Answer : Buck converter or Step down converter: Buck converter is a step-down converter. The buck converter step-down the output voltage and step up the output current. Buck converter is a DC to DC converter. ... load. The output voltage is controlled by controlling on period and off period.
Description : Explain the operation of full bridge converters with their different operating modes. State its advantages and disadvantages.
Last Answer : Full bridge converter: Full bridge converter provides isolation between input and output. Full bridge converter is used for step up or step down the input voltage. Full bridge converter consists of four power semiconductor ... Require filter on both input and output.
Description : single phase full converter
Last Answer : single phase full converter
Description : Explain flyback converter and draw its waveforms.
Last Answer : Flyback converter: A flyback converter is used for getting DC output and for isolating input mains and output voltage. A flyback converter is like a buck-boost converter with input and output isolated. There ... during the off time transformer transfer the energy to load.
Description : Explain buck boost converter and draw its waveforms.
Last Answer : Buck-Boost converter: The buck-boost converter consists of a transistor for switching purpose, diode, inductor, and capacitor. Buck-boost converter is the combination of the buck converter and boost ... In buck-boost converter both input current and diode current are discontinuous.
Description : what is Cuk converter and draw its waveforms.
Last Answer : Cuk converter: Cuk converter is the series combination of boost and the buck converter. The Cuk converter is the DC to DC converter whose output voltage is greater than or less the than the input ... controlling the switch duty cycle the output voltage can be controlled.
Description : An amplifier is said to suffer from distortion when its output is - (1) low (2) different from input (3) noisy (4) larger than its input
Last Answer : (3) noisy Explanation: Amplifier Distortion can take on many forms such as Amplitude, Frequency and Phase Distortion due to Clipping. For a signal amplifier to operate correctly without any distortion to the output signal, it requires some form of DC Bias on its Base or Gate terminal.
Description : Benefits of negative feedback include A. less distortion B. increased bandwidth C. low output resistance D. all of above
Last Answer : all of above
Description : When you are testing a piece of equipment for intermodulation distortion, what should the output of the equipment look like?
Last Answer : An exact reproduction of the input.
Description : How does dc bias added to the input signal correct the distortion in the output signal?
Last Answer : The dc bias moves the input signal away from the step in the magnetism curve. This prevents the input signal from crossing the zero-point of the magnetism curve.
Description : The type of power amplifier that exhibits crossover distortion in its output is : (A) Class A (B) Class B (C) Class AB (D) Class C
Last Answer : The type of power amplifier that exhibits crossover distortion in its output is Class B
Description : A weighted resistor digital to analog converter using N bits requires a total of (A) N precision resistors. (B) 2N precision resistors. (C) N + 1 precision resistors. (D) N – 1 precision resistors.
Last Answer : (A) N precision resistors.
Description : A particle in simple Harmonic Motion while passing through mean position will have a.Maximum kinetic energy and minimum potential energy b.Average kinetic energy and average potential energy c. ... energy d.Maximum kinetic energy and maximum e.Minimum kinetic energy and minimum potential energy
Last Answer : a. Maximum kinetic energy and minimum potential energy
Description : A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to ... final pressures respectively) (A) Logarithmic (B) Arithmetic (C) Geometric (D) Harmonic
Last Answer : (C) Geometric
Description : What is the best method for bending aluminum square tubing while keeping a tight radius and minimum distortion?
Last Answer : Buy a pipe bender from a hardware store. Then fill the pipe with water and freeze it, this will stop it form compressing.
Description : The four-quadrant dual operation requires (a) Two full converters in series (b) Two full converters connected back to back (c) Two full converters connected in parallel. (d) Two semiconverters connected back to back
Last Answer : The four-quadrant dual operation requires Two full converters connected back to back
Description : A four -quadrant operation requires two full converters connected in (1) Series (3) Back to back (2) Parallel (4) Series Cascade
Last Answer : A four-quadrant operation requires two full converters connected in Parallel
Description : Mr. Sharma decided to walk down the escalator of a tube station. He found that if he walks down 26 steps, he requires 30 seconds to reach the bottom. However, if he steps down 34 stairs he would only ... time he steps off the last step at the bottom, find out the height of the stair way in steps?
Last Answer : Answer: 46 steps.