Oscillators

Oscillators1. Which condition must exist for a circuit to oscillateIt must have a negative feedback sufficient to cancel the inputIt must have gain of less than 1It must have a positive feedbackIt must be realized2. Which is the following is not an essential parts of an oscillatorSource of energy that supply the losses in tank circuitA resistor IC combination circuitResonant circuit consist of inductance and capacitanceRegenerative feedback circuit3. The energy of oscillator can be sourced by Coupling a small coil close to the tubeCapacitive and inductive coupling from the tuned circuitInserting a resistor in the grid circuitConnecting the capacitor across the supply4. _______ is the progressive decay with time in the amplitude of the free oscillation in a circuitDecrementPulse decay time DampingDancing

5. ___________ is the characteristic of an oscillator that enables it to sustain oscillation after removal of the control stimulus MomentumDampingFlywheel effectForced oscillation

6. What type of feedback aids an input signal?Inductive and capacitiveIndirect feedbackDegenerative or negative feedbackDirect feedback7. What are the two methods used for feedback coupling?Inductive and capacitiveCapacitive and impedanceResistive and inductiveResistive and capacitive

8. Which is oscillator uses a tickler coil for feedbackArcArmstrongColpittsHartley

9. Which oscillator uses a tapped inductor for feedback?ArcArmstrongColpittsHartley

10. Which oscillator uses split capacitors for feedbackHartleyColpitts Armstrongarc

11. It is used to produce a sine-wave output of constant amplitude and of fairty constant frequency within the rf rangeArmstrong oscillatorColpitts oscillatorHartley oscillatorFlywheel effect12. What type of circuit is used to produce square or rectangular waves?Sinusoidal generatorMulti-vibratorNon-sinusoidal generatorWave generator13. What type of multivibrator has one stable stateNonstableMultistableBistableAstable

14.Multivibrators,blocking oscillators and saw tooth and trapezoidal wave generators are classified as:Resonant circuitsSynchronized generatorsFiltersRelaxation oscillators15. Monostable multivibrator is usually for Pulse stretchingOscillationDampingFrequency determining16. The three types of mutivibrators are a. Astable b. monostable c. bistable d. multistableA, B,C and DA,C and DB, C, and DA, B, and C17. In an astable multivibrator which components determine the pulse repetition frequency?LC coupling networksRZC coupling networksDirect CouplingImpedance Coupling18. In an astable multivibrator which components determine the pulse repetition frequency?LC coupling networksRZC coupling networksDirect CouplingImpedance Coupling

19. What is another name for the monosatble multivibrator?Frequency MultivibratorOne-shotOne-HitMultishot20. The three networks used for frequency determining devices a. lc b. rc c. crystal d. mechanicalA,B and CB, C and CA,B and DA, B ,C and D21. What is another name for non sinusoidal oscillators?Square wave oscillatorsStiff oscillatorRelaxation oscillatorSine wave oscillator22. What is a non-rotating device that produces alternating current?StatorAlternatorOscillatorDynamo

23. What type of feedback aids an input signal?Degenerative feedbackNegative feedbackInverse feedbackRegenerative feedback24. What are the two methods used for feedback coupling?Inductive and capacitiveCapacitive and impedanceResistive and inductiveResistive and capacitive25. Which oscillator uses a tickler coil for feedback?ArcArmstrongColpittsHartley26. Which oscillator uses a tapped coil for feedback?ArcArmstrongColpitts Hartley

27. Which oscillator uses tapped capacitors for feedback?HartleyColpittsArmstrong Arc

28. ________ is a measure of the degree to which is a constant frequency output is approachedFrequency sensitivityFrequency selectivityFrequency stabilityfree running frequency 29. It is used to produce a sine wave output of constant amplitude and of fairly constant frequency within the rf range Armstrong oscillatorColpiits oscillatorHarley oscillatorFlywheel effect

30. What type of multivibrator has one stable state?MonostableMultistableBistableAstable

31. The time for one complete cycle of a pulse is called the ________MonostableMultistableBistableAstable

32. The number of times in one second that the one pulse cycle repeats itself is calledPulse repetition timePulse repetition frequencyPulse repetition ratePulse repetition wavelength33. A waveform that resembles the teeth of a saw bladeTriangular waveformSaw tooth waveformSquare waveformSinusoidal waveform34. The type of circuit most often used to generate square or rectangular waves is the multivibrator OscillatorMultivibratorAmplifierResonant circuit35. multivibrators, blocking oscillators and saw tooth and trapezoid wave generators are classified asResonant circuitsSynchronized generatorsFiltersRelaxation oscillators

36. What type of crystals are sliced parallel to the sides of the raw crystal?XYZA

37. To what lc oscillator circuit is a pierce similar?ArmstrongHartleyColpitts Clapp

38. One methods of synthesizing frequenciesLC circuitsRC circuitsCapacitorsCrystals

39. In what type of circuit does flywheel effect occur? LC circuitsRC circuitsCrystalPierce

40. How many thermal runaway in transistor oscillators be prevented? Add stabilizing circuitAdd emitter resistorAdd base resistorReduce input current

41. In what way is a Hartley oscillators similar to an armstrong?Resistive feedbackInductive feedbackCrystal feedbackCapacitive feedback

42. What type of feed has current flowing through an RFC?ShuntSeriesSeries-shuntAny of these43. What is the output of a multivibrator rich in harmonics?Non sinusoidal waveSinusoidal waveTriggersSaw tooth

43. A method of producing a lower frequency parasitic oscillation?LC charge and dischargeRC charge and dischargeRLC inputsRLC inputs and outputs