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 :?
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
51450. Which Indian become the President of International Court of Justice?
© 2002-2017 Omega Education PVT LTD...Privacy | Terms And Conditions