Description : Which junction of the transistor in the common-emitter detector detects the modulation envelope?
Last Answer : Emitter-base junction
Description : Sound waves transmitted from a source are sometimes weak when they reach the detector. What instrument is needed to boost the weak signal?
Last Answer : An amplifier.
Description : An error signal is the difference between what two quantities fed to the CT (error detector)?
Last Answer : Input signal and feedback.
Description : What is the input current in the common-emitter circuit?
Last Answer : Base current (IB).
Description : In the output of an ac error detector, what indicates the (a) direction and (b) amount of control necessary for correspondence?
Last Answer : (a) Phase. (b) Amplitude.
Description : The common-emitter transistor circuit can amplify a small current signal because a small change in the signal current produces one of the following. Does the change in signal produce a large change in the: w) emitter-base voltage x) base current y) collector current z) collector voltage
Last Answer : ANSWER: Y -- COLLECTOR CURRENT
Description : A temperature instrumentation system for an engine room console consists of a resistance temperature detector (RTD), a measuring bridge circuit, and a meter (or alarm circuit).Which of the following ... is zero. D. The input voltage of the resistance bridge is the constant temperature signal.
Last Answer : Answer: C
Description : The minimum optical power a light detector can receive and still produce a usable electrical output signal. ∙ A. light responsivity ∙ B. light sensitivity ∙ C. light collectivity ∙ D. illumination
Last Answer : B. light sensitivity
Description : The term responsivity as it applies to a light detector is best described as ∙ A. the time required for the signal to go from 10 to 90 percent of maximum amplitude ∙ B. the ratio of the diode ... . the ratio of the input power to output power ∙ D. the ratio of output current to input current
Last Answer : the ratio of the diode output current to the input optical power
Description : The minimum optical power a light detector can receive and still produce a usable electrical output signal.
Last Answer : light sensitivity
Description : The input to a coherent detector is DSB-SC signal plus noise. The noise at the detector output is: (1) The in-phase component (2) The quadrature-component (3) Zero (4) The envelope
Last Answer : The input to a coherent detector is DSB-SC signal plus noise. The noise at the detector output is: Zero.
Description : A common-emitter circuit has an input voltage of 0.1 volt, an output voltage of 2.0 volts, an input current of 0.5 milliamps, and an output current of 10 milliamps. What is the power gain? A. 20 B. 40 C. 400 D. 4000
Description : Draw output characteristics of common emitter [CE] configuration and explain active, saturation and cut-off regions in detail.
Last Answer : Characteristics of common emitter [CE] configuration Explanation : (1) Active Region: In this region collector junction is reverse biased and emitter junction is forward biased. It is ... the transistor collector current is approximately given by VCC / RC and independent of base current.
Description : What are the four most common materials used in semiconductor detector fabrication?
Last Answer : Silicon, gallium arsenide, germanium, and indium phosphide.
Description : To what circuit arrangement is a common-base detector equivalent?
Last Answer : A diode detector followed by a stage of audio amplification.
Description : Which junction acts as the detector in a common-base detector?
Last Answer : Emitter-base junction.
Description : Besides eliminating the emitter-base battery, what other advantages can different biasing methods offer?
Last Answer : Compensation for slight variations in transistor characteristics and changes in transistor conduction because of temperature variations.
Description : the voltage drop across RS and R1 determines the amount of base-emitter ____ for Q1.
Last Answer : Bias.
Description : What is the polarity of the first alternation of the tank circuit in an emitter-loaded npn pulsed oscillator?
Last Answer : Negative
Description : What causes the change in collector current in an emitter injection modulator?
Last Answer : Gain is varied by changing the voltage on the emitter.
Description : Which of the following combinations has no phase inversion of the signal? A) Two CE stages B) CE and CC stages C) Three CE stages D) CE stage and emitter follower.
Last Answer : A) Two CE stages
Description : What is the difference between an RC and an RL differentiator in terms of where the output is developed? is developed?
Last Answer : . In an RC circuit the output is taken across the resistor. In the RL circuit the output is taken across the inductor.
Description : What is the condition of the diode in a series limiter when an output is developed? In a parallel limiter?
Last Answer : Conducting, cutoff.
Description : A positive damper clamps which extremity of the output signal to 0 volts?
Last Answer : Most negative.
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 : 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.
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 : In the power amplifier shown in figure 2-10, what two signals are mixed to produce the output signal?
Last Answer : Local oscillator and coherent oscillator.
Description : what causes the initial and final pulses on the receiver output signal?
Last Answer : Leakage from the duplexer.
Description : Why does using ac vice dc bias voltage result in a stronger output signal?
Last Answer : Because an ac bias voltage of the proper frequency and level places the input signal away from both steps in the magnetism curve. The result is two undistorted output signals that are combined into one strong output.
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 : In signal generators, what device is used to regulate the voltage of the output signal?
Last Answer : Attenuator.
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 : Why is detector saturation not generally a problem in fiber optic communications systems?
Last Answer : Because fiber optic communications systems operate at low optical power levels.
Description : For efficient operation, should a detector have a high or low responsivity at the operating wavelength?
Last Answer : High.
Description : Describe the operation of an optical detector
Last Answer : It is a transducer that converts an optical signal into an electrical signal. It does this by generating an electrical current proportional to the intensity of incident optical radiation.
Description : What is the function of the detector?
Last Answer : To extract the modulating audio signal.
Description : How can a peak detector for pam be modified to detect pdm?
Last Answer : By making the time constant for charging the capacitor at least 10 times the maximum received pulse width.
Description : What is the time constant of the resistor and capacitor in a peak detector for pam?
Last Answer : At least 10 times the interpulse period.
Description : What characteristic of a pulse does a peak detector sample?
Last Answer : Pulse amplitude or pulse duration
Description : In its simplest form, what functions must a radar detector be capable of performing?
Last Answer : Detecting the presence of rf energy.
Description : How is a quadrature detector changed when used for phase demodulation?
Last Answer : The quadrature grid signal is excited by a reference from the transmitter.
Description : Name two advantages of the gated-beam detector.
Last Answer : Extreme simplicity, few components, and ease of adjustment.
Description : What condition must exist on both the limiter and quadrature grids for current to flow in a gated-beam detector?
Last Answer : Both grids must be positively biased