<<= Back Next =>>
You Are On Multi Choice Question Bank SET 1028

51401. In the Wien bridge oscillator, which of the following is (are) frequency-determining components?





51402. Determine the input impedance with feedback for a voltage-series feedback having A = –100, R1 = 15 k, Ro = 20 k, and a feedback of = –0.25.





51403. A certain oscillator has a tap on the inductor in the tank circuit. This oscillator is probably





51404. At parallel resonance, the impedance of a crystal is





51405. Refer to this figure. Assuming it is configured as an oscillator and if you desired to reduce the duty to less than 50%, the following circuit change would need to be made.





51406. Calculate the fr of a lead-lag network if R1 = R2 = 6.8 k, and C1 = C2 = 0.05 F.





51407. Which of the following is (are) feedback?





51408. What is the relationship between the series and parallel resonant frequencies of a quartz crystal?





51409. An op-amp integrator has a square-wave input. The output should be





51410. The frequency distortion arising because of varying amplifier gain with frequency is considerably reduced in a negative-voltage feedback amplifier circuit.



51411. An amplifier is stable if the absolute magnitude of A is ________.




51412. ________ is a frequency-determining component in a unijunction oscillator.





51413. In the Colpitts oscillator, the elements X1 and X2 are ________ and X3 is a(n) ________.





51414. In a Hartley oscillator, the elements X1 and X2 are ________ and X3 is a(n) ________.





51415. A feedback amplifier has a ________ upper 3-dB frequency and a ________ lower 3-dB frequency compared to an amplifier without feedback.





51416. What is the gain at the origin of the Nyquist plot?





51417. Positive feedback results in ________.





51418. In the Wien bridge oscillator with R1 = R2 = R and C1 = C2 = C, a ratio of R3 to R4 will provide sufficient loop gain for the circuit to oscillate.





51419. In the phase-shift oscillator, the operating frequency is determined by ________.





51420. In the Barkhausen criterion, the loop gain A is equal to ________.





51421. Negative feedback results in ________.





51422. With feedback, , the overall gain of the circuit is reduced by a factor ________ where A is the gain without the feedback.



51423. Series-feedback connections tend to ________ the input resistance. Shunt feedback connections tend to ________ the input resistance.





51424. In practice, A is made ________ and the system is started oscillating by amplifying noise voltage, which is always present.





51425. Voltage feedback connections tend to ________ the output impedance. Current feedback connections tend to ________ the output impedance.





51426. In the phase-shift oscillator, the gain of the amplifier stage must be ________.




51427. The series-resonant impedance of a crystal oscillator is ________.





51428. An amplifier with negative feedback has ________ bandwidth than (as) the amplifier without feedback.





51429. The parallel-resonant impedance of a crystal oscillator is ________.





51430. In a Nyquist plot, as the frequency increases, the phase shift between input and output signals ________.





51431. At the series-resonant frequency, the amount of positive feedback is ________.





51432. Since the crystal losses represented by R are small, the equivalent crystal Q (quality factor) is ________.





51433. In the Colpitts oscillator, the frequency is determined by ________ .





51434. Typically, a unijunction transistor has a stand-off ratio from ________ to ________.





51435. Crystal oscillators are used whenever a(n) ________ level of stability is required.





51436. The feedback network in a Colpitts oscillator contains two series capacitors and a parallel inductor.



51437. The positive feedback voltage in an oscillator has no net phase shift.



51438. Crystal oscillators are inherently unstable.



51439. For a Wien-bridge oscillator, resonance occurs when Vout/Vin = 1.



51440. LC feedback elements are normally used in oscillators for frequencies greater than 1 MHz.



51441. The frequency in a VCO can be varied with a DC voltage.



51442. Oscillators operate on negative feedback.



51443. The start-up gain of an oscillator must be greater than 1.



51444. The feedback signal in a Hartley oscillator is derived from an inductive voltage in the tank circuit.



51445. In the astable mode, a 555 timer is connected as a free-running relaxation oscillator.



51446. Calculate the value of C1 = C2 for the Wien bridge oscillator to operate at a frequency of 20 kHz. Assume R1 = R2 = 50 k and R3 = 3R4 = 600?





51447. Only the condition A = ________ must be satisfied for self-sustained oscillations to result.





51448. At what phase shift is the magnitude of A at its maximum in the Nyquist plot?





51449. Find the odd one :?





51450. Which Indian become the President of International Court of Justice?





<<= Back Next =>>
Terms And Service:We do not guarantee the accuracy of available data ..We Provide Information On Public Data.. Please consult an expert before using this data for commercial or personal use | Powered By:Omega Web Solutions
© 2002-2017 Omega Education PVT LTD...Privacy | Terms And Conditions