A phase-locked loop (PLL) is a feedback circuit consisting of a

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A phase-locked loop (PLL) is a feedback circuit consisting of a phase detector, low-pass filter, VCO.

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Related questions

Which of the following applications include a phase-locked loop (PLL) circuit?

Description : Which of the following applications include a phase-locked loop (PLL) circuit?  (1) Modems (2) AM decoders (3) Tracking filters (4) All of these 

Last Answer : All of these.

A negative feedback loop returning a voltage to the input raised the input impedance and making the circuit a better

Description : A negative feedback loop returning a voltage to the input raised the input impedance and making the circuit a better

Last Answer : A negative feedback loop returning a voltage to the input raised the input impedance and making the circuit a better voltage sensor

Which of the following is the basic synthesizer circuit? A. Frequency divider B. Frequency multiplier C. PLL D. Mixer

Description : Which of the following is the basic synthesizer circuit? A. Frequency divider B. Frequency multiplier C. PLL D. Mixer

Last Answer : C. PLL

In the ideal closed loop operational amplifier, the gain depends on

Description : In the ideal closed loop operational amplifier, the gain depends on (A) value of the series component (B) value of the feedback component (C) on the operational amplifier itself (D) both A and B

Last Answer : In the ideal closed loop operational amplifier, the gain depends on (A) value of the series component (B) value of the feedback component (C) on the operational amplifier itself (D) both A and B

Which of the following is not true: A) An oscillator is a circuit that converts DC to AC B) An oscillator is an amplifier that supplies its own input signal C) All oscillators generate sine waves D) In phase feedback is called positive Feedback

Description : Which of the following is not true: A) An oscillator is a circuit that converts DC to AC B) An oscillator is an amplifier that supplies its own input signal C) All oscillators generate sine waves D) In phase feedback is called positive Feedback

Last Answer : C) All oscillators generate sine waves

Could twitter, friendfeed, and other text status services cause a eternal feedback loop between them?

Description : Could twitter, friendfeed, and other text status services cause a eternal feedback loop between them?

Last Answer : What do you mean? Where updating your Twitter would update your FriendFeed, which would update your Twitter, which would update your FriendFeed, which would update your Twitter, which would update your ... of abuse limiting in place to ensure that a flurry of the same update couldn't happen.

In which system we get feedback? a.Open-loop system b.Machine control system c.Closed-loop system d.None of the above

Description : In which system we get feedback? a.Open-loop system b.Machine control system c.Closed-loop system d.None of the above

Last Answer : c.Closed-loop system

What type of feedback loop is most common in nature and which more commonly results from human action?

Description : What type of feedback loop is most common in nature and which more commonly results from human action?

Last Answer : Need answer

In the illustrated amplifier, the RESET potentiometer A1R2 sets the stability of the control loop by changing the reset time constant. As the potentiometer is turned clockwise _________. EL-0060 A. the gain is increased B. the stability is increased by slowing the response time C. feedback is increased to the summing point at terminal 5 D. response time is increased decreasing stability

Description : In the illustrated amplifier, the RESET potentiometer A1R2 sets the stability of the control loop by changing the reset time constant. As the potentiometer is turned clockwise _________. EL-0060 A. ... is increased to the summing point at terminal 5 D. response time is increased decreasing stability

Last Answer : Answer: B

What is an auto-associative network? a) a neural network that contains no loops b) a neural network that contains feedback c) a neural network that has only one loop d) a single layer feed-forward neural network with pre-processing

Description : What is an auto-associative network? a) a neural network that contains no loops b) a neural network that contains feedback c) a neural network that has only one loop d) a single layer feed-forward neural network with pre-processing

Last Answer : b) a neural network that contains feedback

Computers that control processes accept data in a continuous a) data traffic pattern b) data highway c) infinite loop d) feedback loop e) None of these 44. What refers to a

Description : Computers that control processes accept data in a continuous a) data traffic pattern b) data highway c) infinite loop d) feedback loop e) None of these 44. What refers to a

Last Answer : c) infinite loop

select the correct response from the choices given in the parentheses. Q-20. In a closed-loop configuration the output signal is determined by (the input signal, the feedback signal, both).

Description : select the correct response from the choices given in the parentheses. Q-20. In a closed-loop configuration the output signal is determined by (the input signal, the feedback signal, both).

Last Answer : Both the input signal and the feedback signal.

In a typical velocity servo block diagram what device is placed in the feedback loop that is not present in the position servo?

Description : In a typical velocity servo block diagram what device is placed in the feedback loop that is not present in the position servo?

Last Answer : Tachometer.

An auto-associative network is: a) a neural network that contains no loops b) a neural network that contains feedback c) a neural network that has only one loop d) a single layer feed-forward neural network with pre-processing

Description : An auto-associative network is: a) a neural network that contains no loops b) a neural network that contains feedback c) a neural network that has only one loop d) a single layer feed-forward neural network with pre-processing

Last Answer : b) a neural network that contains feedback

A bidirectional feedback loop links computer modelling with: a. artificial science b. heuristic processing c. human intelligence d. cognitive science

Description : A bidirectional feedback loop links computer modelling with: a. artificial science b. heuristic processing c. human intelligence d. cognitive science

Last Answer : d. cognitive science

For a feedback amplifier, if the loop gain is much greater than unity, the closed loop gain will be equal to

Description : For a feedback amplifier, if the loop gain is much greater than unity, the closed loop gain will be equal to

Last Answer : For a feedback amplifier, if the loop gain is much greater than unity, the closed loop gain will be equal to inverse of feedback factor

Negative feedback in a closed-loop control system DOES NOT

Description : Negative feedback in a closed-loop control system DOES NOT (A) reduce the overall gain (B) reduce bandwidth (C) improve disturbance rejection (D) reduce sensitivity to parameter variation

Last Answer : Negative feedback in a closed-loop control system DOES NOT reduce bandwidth

An OP amp has an open loop gain of 1,00,000. If the feedback fraction is 0.02, the approximate closed loop...

Description : An OP amp has an open loop gain of 1,00,000. If the feedback fraction is 0.02, the approximate closed loop gain is (a) 1 (b) 1,00,000 (c) 50 (d) 0.02

Last Answer : The closed loop gain Ag = G/(1+G*f) Where G is the open loop gain and f is the feedback fraction  So Ag = 49.975

In closed loop control system, with positive value of feedback gain the overall gain of the system will

Description : In closed loop control system, with positive value of feedback gain the overall gain of the system will

Last Answer : In closed loop control system, with positive value of feedback gain the overall gain of the system will decrease.

To check the three line fuses of a three-phase system consisting of a three-phase motor, you must _____________. A. place the starter in the 'stop' position B. make sure the motor is operating at full load to guard against a false reading C. place the leads across the 'hot' ends of the fuses D. place the leads across the bottom ends of the fuses

Description : To check the three line fuses of a three-phase system consisting of a three-phase motor, you must _____________. A. place the starter in the 'stop' position B. make sure the motor is operating at full ... leads across the 'hot' ends of the fuses D. place the leads across the bottom ends of the fuses

Last Answer : Answer: A

At the beginning of which phase of mitosis does each duplicated and condensed chromosome consisting of two identical sister chromatids align along the cell equator?

Description : At the beginning of which phase of mitosis does each duplicated and condensed chromosome consisting of two identical sister chromatids align along the cell equator?

Last Answer : Metaphase

Write the Abbreviation for the following File Extension 1. FMB 2. MMB 3. PLL?

Description : Write the Abbreviation for the following File Extension 1. FMB 2. MMB 3. PLL?

Last Answer : FMB ----- Form Module Binary. MMB ----- Menu Module Binary. PLL ------ PL/SQL Library Module Binary.

Mention some typical applications of PLL

Description : Mention some typical applications of PLL

Last Answer : • Frequency multiplication/division • Frequency translation • AM detection • FM demodulation • FSK demodulation.

What is the purpose of having a low pass filter in PLL?

Description : What is the purpose of having a low pass filter in PLL?

Last Answer : *It removes the high frequency components and noise. *Controls the dynamic characteristics of the PLL such as capture range, lock-in range,band-width and transient response. *The charge on the filter capacitor gives a short- time memory to the PLL

Define capture range of PLL.

Description : Define capture range of PLL.

Last Answer : The range of frequencies over which the PLL can acquire lock with an input signal is called the capture range. It is expressed as a percentage of the VCO free running frequency.

Define lock-in range of a PLL.

Description : Define lock-in range of a PLL.

Last Answer : The range of frequencies over which the PLL can maintain lock with the incoming signal is called the lock-in range or tracking range. It is expressed as a percentage of theVCO free running frequency.

What are the three stages through which PLL operates?

Description : What are the three stages through which PLL operates?

Last Answer : 1.Free running 2.Capture 3.Locked/ tracking

Mention some areas where PLL is widely used.

Description : Mention some areas where PLL is widely used.

Last Answer : 1.Radar synchronizations 2. Satellite communication systems 3. Air borne navigational systems 4. FM communication systems 5.Computers.

List the basic building blocks of PLL

Description : List the basic building blocks of PLL

Last Answer : 1.Phase detector/comparator 2.Low pass filter 3.Error amplifier 4.Voltage controlled oscillator

Draw and explain PLL as an FM demodulator.

Description : Draw and explain PLL as an FM demodulator.

Last Answer : Explanation:- FM signal which is to be demodulated is applied to input of PLL.VCO output must be identical to input signal if PLL is to remain locked. As PLL is locked, VCO ... error voltage represents the modulating signal. Thus at the error amplifier output we get demodulated FM output.

Draw and label PLL based FM detector.

Description : Draw and label PLL based FM detector.

Last Answer : Draw and label PLL based FM detector.

What is PLL? Explain its operation with a block diagram.

Description : What is PLL? Explain its operation with a block diagram.

Last Answer : PLL - A phase-locked loop or phase lock loop is a control system that generates an output signal whose phase is related to the phase of an input signal Block diagram  ... to the input frequency. The phase - locked loop goes through three states free running capture and phase lock.

Draw block diagram of PLL as a FM demodulator. Explain function of each block.

Description : Draw block diagram of PLL as a FM demodulator. Explain function of each block.

Last Answer : Operation:  The FM signal which is to be demodulated is applied at the input of the PLL.  the PLL is locked to the FM  The error voltage produced at ... using PLL ensures a high Linearity, between the instantaneous input frequency and VCO control voltage (error amplifier output)

In a PLL, lock occurs when the

Description : In a PLL, lock occurs when the (A) input frequency and the VCO frequency are the same (B) Phase error is 1800 (C) VCO frequency is double the input frequency (D) Phase error is 900

Last Answer : In a PLL, lock occurs when the input frequency and the VCO frequency are the same

A series circuit consisting of three resistors has a current of 3 amps. If R1 = 20 ohms, R2= 60 ohms, and R 3 = 80 ohms, what is the (a) total resistance and (b) source voltage of the circuit?

Description : A series circuit consisting of three resistors has a current of 3 amps. If R1 = 20 ohms, R2= 60 ohms, and R 3 = 80 ohms, what is the (a) total resistance and (b) source voltage of the circuit?

Last Answer : (a) 160 ohms. (b) 480 ohms

The speed of a three-phase squirrel-cage induction-type motor operating in a fixed frequency system is varied by changing the _____________. A. number of phases to the motor B. number of stator poles C. locked rotor current D. resistance of the rotor winding

Description : The speed of a three-phase squirrel-cage induction-type motor operating in a fixed frequency system is varied by changing the _____________. A. number of phases to the motor B. number of stator poles C. locked rotor current D. resistance of the rotor winding

Last Answer : Answer: B

What transmission method uses a stable cw reference oscillator, which is locked in phase with the transmitter frequency?

Description : What transmission method uses a stable cw reference oscillator, which is locked in phase with the transmitter frequency?

Last Answer : Pulse-Doppler.

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated

Description : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor ... Hz supply is  (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A

Last Answer : The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is 45.0 A 

A 3-phase induction motor under locked rotor condition and with stator supply, induces

Description : A 3-phase induction motor under locked rotor condition and with stator supply, induces (A) small voltage at slip frequency (B) large voltage at rotor frequency (C) zero voltage at zero frequency (D) large voltage at slip frequency

Last Answer : A 3-phase induction motor under locked rotor condition and with stator supply, induces (A) small voltage at slip frequency (B) large voltage at rotor frequency (C) zero voltage at zero frequency (D) large voltage at slip frequency

A tuned circuit has a Q of 100 at its resonant frequency of 500 kHz. Its bandwidth is _____kHz.

Description : A tuned circuit has a Q of 100 at its resonant frequency of 500 kHz. Its bandwidth is _____kHz. (A) 50000 (B) 0.2 (C) 600 (D) 5

Last Answer : A tuned circuit has a Q of 100 at its resonant frequency of 500 kHz. Its bandwidth is 5 kHz.

If the resistance total in a series circuit doubles, current will:

Last Answer : If the resistance total in a series circuit doubles, current will: be halved

If an AC generator experiences voltage failure, the cause may be _____________. A. an open in the field circuit B. the brushes shifting out of the neutral plane C. excessive locked-rotor current D. a rotating slip ring

Description : If an AC generator experiences voltage failure, the cause may be _____________. A. an open in the field circuit B. the brushes shifting out of the neutral plane C. excessive locked-rotor current D. a rotating slip ring

Last Answer : Answer: A

increases the steady state accuracy. (a) Integrator (b) Differentiator (c) Phase lead compensator (d) Phase lag compensator Ans:A 10.As a result of introduction of negative feedback which of the following will not decrease ? (a) Band width (b) Overall gain (c) Distortion (d) Instability

Description : increases the steady state accuracy. (a) Integrator (b) Differentiator (c) Phase lead compensator (d) Phase lag compensator Ans:A 10.As a result of introduction of negative feedback which of the following will not decrease ? (a) Band width (b) Overall gain (c) Distortion (d) Instability

Last Answer : Ans: A

The major function of transistor. Q2 is A) It provides voltage gain B) It provides the feedback signal C) It isolates the oscillator from loading effects D) It provides a phase shift.

Description : The major function of transistor. Q2 is A) It provides voltage gain B) It provides the feedback signal C) It isolates the oscillator from loading effects D) It provides a phase shift.

Last Answer : ) It provides a phase shift.

What conditions are required for an amplifier to oscillate A) There must be feedback B) The feedback must be in phase C) The gain must be greater than the loss D) All the above are regd.

Description : What conditions are required for an amplifier to oscillate A) There must be feedback B) The feedback must be in phase C) The gain must be greater than the loss D) All the above are regd.

Last Answer : B) The feedback must be in phase

Which components provide the regenerative feedback signal in the phase-shift oscillator?

Description : Which components provide the regenerative feedback signal in the phase-shift oscillator?

Last Answer : Resistor-capacitor networks.

In Knowledge Acquisition Phase, the student teacher (a) Prepares micro lesson plans for the select skills (b) Practice the skill (c) Gives feedback by observers (d) Gives outline for the preparation of micro lesson plan

Description : In Knowledge Acquisition Phase, the student teacher (a) Prepares micro lesson plans for the select skills (b) Practice the skill (c) Gives feedback by observers (d) Gives outline for the preparation of micro lesson plan

Last Answer : (d) Gives outline for the preparation of micro lesson plan

Differentiate between positive and negative feedback on the basis of . (i) overall phase shift (ii) voltage gain (iii) stability (iv) applications

Description : Differentiate between positive and negative feedback on the basis of . (i) overall phase shift (ii) voltage gain (iii) stability (iv) applications 

Last Answer : Compare positive feedback and negative feedback on the basis of: (i) Gain (ii) Bandwidth (iii) Phase shift (iv) Stability

For a stable feedback control system, the phase margin is

Description : For a stable feedback control system, the phase margin is  a) always positive b) always negative c) may be positive or negative d) always greater than 180o

Last Answer : For a stable feedback control system, the phase margin is always positive