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).

1 Answer

Answer :

Both the input signal and the feedback signal.

Related questions

Description : In the inverting configuration, the input signal is applied to the (a) (inverting, noninverting) input and the feedback signal is applied to the (b) (inverting, noninverting) input.

Last Answer : a. Inverting. b. Inverting.

Description : What does the term "closed-loop" mean in the closed-loop configuration of an operational amplifier?

Last Answer : The use of degenerative (negative) feed-back

Description : What type of feedback aids an input signal?

Last Answer : Regenerative or positive

Description : In the inverting configuration when the noninverting input is grounded, the inverting input is at (signal, virtual) ground

Last Answer : Virtual.

Description : In the inverting configuration, what is the voltage (for all practical purposes) at the inverting input to the operational amplifier if the input signal is a 1-volt, peak-to-peak sine wave?

Last Answer : 0 volts.

Description : Which transistor configuration provides a phase reversal between the input and output signals?

Last Answer : Common emitter.

Description : Which terminology deals with the excitation or stimulus applied to the system from an external source for the generation of an output? a. Input signal b. Output signal c. Error signal d. Feedback signal

Last Answer : Ans: A

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 : What characteristic is determined by the time required for a voltage wave to travel from the input end of an artificial transmission line to the output end and back again?

Last Answer : Pulse width

Description : What characteristic is determined by the time required for a voltage wave to travel from the input end of an artificial transmission line to the output end and back again?

Last Answer : Pulse width.

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

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

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

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

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.

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

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.

Description : . When you select the time base to display a signal, should the time base be the same, higher, or lower than the input signal?

Last Answer : Lower.

Description : In a circuit such as that shown in figure 3-16, if R1 has a value of 50 ohms and R2 has a value of 250 ohms and the input signal has a value of +10 millivolts, what is the value of the output signal?

Last Answer : 60 millivolts.

Description : In a circuit such as that shown in figure 3-15, if R1 has a value of 100 ohms and R2 has a value of 1 kilohm and the input signal is at a value of + 5 millivolts, what is the value of the output signal?

Last Answer : 50 millivolts.

Description : If If the input signals are 180 degrees out of phase with each other and a combined output is taken between the two output terminals, what will the amplitude of the combined output signal be?

Last Answer : 200 millivolts.

Description : If the single-input, differential-output, differential amplifier has an output signal taken between the two output terminals, what will the peak-to-peak amplitude of this combined output be?

Last Answer : 200 millivolts. A-18. a. Differential amplifier

Description : If the two input signals to a difference amplifier are equal in amplitude but neither in phase nor 180 degrees out of phase, what will the output signal be?

Last Answer : . A different shape than the input signals but larger in amplitude.

Description : If only one input signal is used with a difference amplifier, what will the output signal be?

Last Answer : Equal in shape and frequency to the input signal; larger in amplitude than the input signal; half as large in amplitude as when two input signals were used that were 180 degrees out of phase.

Description : If the two input signals to a difference amplifier are equal in amplitude and 180 degrees out of phase, what will the output signal be?

Last Answer : Equal in shape and frequency to each input signal and larger in amplitude by two times than

Description : . If the two input signals of a difference amplifier are in phase and equal in amplitude, what will the output signal be?

Last Answer : No output (the signals will "cancel out").

Description : If the output of a circuit needs to be a complete representation of one-half of the input signal, what class of operation is indicated?

Last Answer : Class B operation.

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

Description : With reference to NC machines, which of the following statements is wrong a.Both closed-loop and open-loop control systems are used b.Paper tapes, floppy tapes and cassettes are used for data storage c.Digitizers may be used as interactive input devices d.Post processor is an item of hardware

Last Answer : c.Digitizers may be used as interactive input devices

Description : What is the advantage of using a closed-servo loop to control load velocity?

Last Answer : The closed-servo loop can regulate load speed under changing conditions.

Description : What basic requirement of a closed-loop system (not present in open-loops) enables present load position to be sensed?

Last Answer : Feedback.

Description : What are the three most common closed-loop capstan drive designs?

Last Answer : a. Differential velocity capstans. b. Dual motors dual capstans. c. Peripheral drive capstans.

Description : How do closed-loop capstan drive tape transports overcome the disadvantages of the open-loop drive design?

Last Answer : Closed loop capstan drive transports use more than one capstan to clamp the tape in the area around the magnetic head.

Description : There are two types of tape transport configurations, open loop capstan drive and closed-loop capstan drive. What are two major disadvantages of open-loop capstan drive tape transports?

Last Answer : a. Only operates in one direction. b. The tape tension and head-to-tape contact can vary.

Description : Which transistor configuration has the highest input resistance?

Last Answer : Common collector.

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

Last Answer : Resistor-capacitor networks.

Description : In an open-loop control system, what action reduces the input to zero so the load is stopped at the desired position?

Last Answer : Usually the operator senses the desired load movement and reduces the input to stop the motor.

Description : In the illustration, the signal from the device connected to terminals 18 and 19 is __________. EL-0046 A. prime mover speed feedback B. loss of control alarm when comparing with the input signal ... slip between the prime mover and the alternator D. to shut down the prime mover if overspeeding

Last Answer : Answer: A

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

Description : Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will   (A) Amplify the noise as much as the signal (B) Reduce the noise (C) Increase the noise (D) Not effect the noise

Last Answer : Negative feedback amplifier has a signal corrupted by noise as its input. The amplifier will Reduce the noise

Description :  A J -K flip-flop with J= 1 and K= 1 has a 20 kHz clock input. The Q output is : (A) Constant and low (B) Constant and high (C) A square wave with 20 kHz frequency (D) A square wave with 10 kHz frequency

Last Answer : a

Last Answer : In a closed-loop system in which the output is the speed of a motor, the output rate control can be used to limit the acceleration of the motor.

Description : Basic operating characteristics of the operational amplifier such as gain and stability are the function of its _____________. A. differential input stage B. power output stage C. feedback circuit D. supply voltages

Last Answer : Answer: C

Description : Comment on the effect of negative feedback on the gain, input and output resistance of the feedback amplifiers.Describe the gain bandwidth product term used in this context and its importance.

Last Answer : Effect of negative feedback: 1. Gain decreases with negative feedback. 2. Input resistance increases with negative feedback. 3. Output resistance decreases with negative feedback. Explanation ... feedback bandwidth increases which means it is stable output on more range of frequency.

Description : An amplifier without feedback has a voltage gain of 50, input resistance 1kΩ and output resistance of 2.5kΩ. The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 would be: (1) 1/11 kΩ (2) 1/5 kΩ (3) 5 kΩ (4) 11 kΩ

Last Answer : An amplifier without feedback has a voltage gain of 50, input resistance 1kΩ and output resistance of 2.5kΩ. The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 would be: 1/11 kΩ

Description : The advantage of using the illustrated circuit configuration is _________. EL-0045 A. high input resistance B. high current gain C. the best stability with an increase in temperature D. the input and output are 180 degrees out of phase

Last Answer : Answer: C

Description : Draw the input and output characteristics of CE configuration.

Last Answer : Input characteristics of CE configuration: Output characteristics of CE configuration:

Description : Compare BJT common base configuration with common collector configuration on the basis of (i) Current gain (ii) Voltage gain (iii) Input impedance (iv) Output impedance

Last Answer : Parameter Common Base Common Collector Current gain Low (About 1) High (1+β) Voltage gain High 1  Input impedance  Low High Output impedance High Low

Description : Signal normally used to study non-ideal flow by stimulus response technique is __________ input. (A) Pulse (B) Step (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)