Positive Feedback Amplifier Question & Answers May 2, 2022 By WatElectronics This article lists 75 Positive Feedback Amplifier MCQs for engineering students. All the Positive Feedback Amplifier Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on their fundamentals on Positive Feedback Amplifier. The feedback system is a circuit in which the output signal is sampled and feedback to the input to form an error signal for driving the system. Feedback systems are used in oscillators, timing circuits as well as other types of electronic circuits. Basic feedback systems are classified as sensing, controlling, and actuating. Mainly exists two types of feedback: Negative feedback and Positive feedback. Positive feedback or a Regenerative amplifier increases the system gain and the possibility of instability may lead to self-oscillation. The overall gain with positive feedback applied will be greater than the gain without feedback. An increase in the system gain would give rise to oscillatory circuit responses, as it increases the effect of the input signal due to magnitude. A positive feedback amplifier can also be an electronic amplifier, based on Op-amplifier. Positive feedback control is obtained by applying an output signal back to the non-inverting terminal via a feedback resistor. 1). A network in which, the output is fed back to the input of second circuit is called______. Feedback Inverting Summing Amplification Hint 2). Feedback circuits are classified as _____ types? Three One Two Four Hint 3). Positive feedback is a______ feedback. Degenerative Indirect Regenerative Negative Hint 4). When the feedback signal is in phase with the input signal then the amplifier is known as_____. Degenerative Indirect Negative feedback Positive feedback Hint 5). Because of increased gain, ______ parameter also increases in a positive fed-back circuit. Distortion Summing Regeneration Degeneration Hint 6). Positive feedback is deployed in _______. Analyzers Oscillators Decoders Timers Hint 7). How many types of feedback connections exists in amplifier? 2 3 4 5 Hint Read more about Differential Amplifier 8). Which of the following metrics can be fed back to input using a series connection. Current Voltage Capacitance Both a and b Hint 9). _________ and Current series are series type feedback connections. Voltage series feedback Current series feedback Voltage shunt feedback Current shunt feedback Hint 10). _________ and Current shunt feedback are shunt type feedback connections. Voltage series feedback Current series feedback Voltage shunt feedback Current shunt feedback Hint 11). _______ feedback generally increases input impedance. Shunt Series Hybrid None of the above Hint 12) _______ feedback generally decreases input impedance. Shunt Series Hybrid None of the above Hint 13)._______ feedback generally increases output impedance. Voltage Current Series Shunt Hint 14). _______ feedback generally decreases output impedance. Voltage Current Series Shunt Hint 15)._______ amplifiers require high input and low output impedances. Feedback Multistage Operational Negative Hint 16). When there is no feedback then the voltage gain is known as______. High gain Low gain Internal gain External gain Hint 17). Voltage gain is represented by _____? A V B C Hint 18). Voltage gain of positive feedback circuit formula is, A=______? A=V_O/V_S A=〖1+V〗_O/V_S A=V_O/〖2V〗_S A=〖V2〗_O/V_S Hint 19). In positive feedback amplifiers, gain stability is________ with increase in applied input? Increases Decreases Constant Null Hint 20). Bandwidth will be ______ in positive feedback amplifiers. Increases Decreases Constant Null Hint 21). V_O is defined as______? Output voltage Input voltage Constant voltage None of the above Hint 22). Where as V_S is defined as______? Output voltage Signal voltage Constant voltage None of the above Hint 23). Feedback circuit is represented by_____? α δ β µ Hint 24). Feedback signal and input signal has a phase shift of________ in a PFA. 0^0 〖180〗^0 〖90〗^0 〖360〗^0 Hint 25)._______ resultant phase shift, will be finally in phase with the input signal in a PFA.. 0^0 〖180〗^0 〖90〗^0 〖360〗^0 Hint Positive Feedback Amplifier Quiz Questions and Answers. 26). Feedback ratio is also known as _______. Feedback amplifier Feedback fraction Feedback gain None of the above Hint 27). Feedback ratio is represented by______. µ β δ α Hint 28). Feedback ratio formula, β=_______? V_f/V_0 1+V_f/V_0 V_f V_0 V_0/V_f Hint 29). Gain of the amplifier with feedback , A_f=________? A/(1+Aβ). A(1+Aβ). (1+Aβ). (1+Aβ)/A Hint 30). Example of positive feedback will be______? Feedback amplifier Electronic amplifier Negative amplifier Wavelet Hint 31). V_out of an Op-amp is applied to the non-inverting input terminal via, ______? V_f R_f I_f L_f Hint 32). As Op-amp amplifies positive input signal, then the output becomes more______. Null Negative Positive Infinity Hint 33). Output becomes _______ at positive supply rail. Non-saturation Saturated Mono saturated Poly saturated Hint 34). If loop gain is positive, then the transfer function A will be_______. G/1-GH G/1+GH 1+GH/G 1-GH/G Hint 35). If GH=1, the system gain A_Vwill be_______? Increase Decrease Null Infinity Hint 36). Positive feedback amplifiers are used in _______ type of circuits. Unilateral Bilateral Active Timing Hint 37). Possibility of instability leads to ______? Forced oscillation Self oscillation Resonance None of the above Hint 38). Series shunt configuration is a ________? Current Controlled Voltage Source Voltage Controlled Current Source Current Controlled Current Source Voltage Controlled Voltage Source Hint Read more about Voltage Regulator 39). Shunt-Shunt Configuration is a_____________? Current Controlled Voltage Source Voltage Controlled Current Source Current Controlled Current Source Voltage Controlled Voltage Source Hint 40). Series-Series Configuration is a __________? Current Controlled Voltage Source Voltage Controlled Current Source Current Controlled Current Source Voltage Controlled Voltage Source Hint 41). Shunt-Series Configuration is a __________? Current Controlled Voltage Source Voltage Controlled Current Source Current Controlled Current Source Voltage Controlled Voltage Source Hint 42). Inverting and non- inverting Op-amp circuits operate with series-shunt feedback producing is known as______? Voltage amplifier Current amplifier Negative feedback amplifier Positive feedback amplifier Hint 43). Transfer gain of series-shunt feedback configuration A_(V ) is __________? V_in / V_out V_out / V_in V_out V_in 〖1+V〗_in / V_out Hint 44). Shunt series feedback is known as _______ feedback. Series current Shunt voltage Series voltage Shunt current Hint 45). Feedback signal is _______ to the output current flowing in the load. Inversely proportional Proportional Related None of the above Hint 46). In shunt-series feedback, the feedback signal is fed-back in _______ with the input. Series Parallel Hybrid None of the above Hint 47). Shunt-series feedback configuration is also known as ______ amplifier? Voltage Current Resistance None Of The Above Hint 48). Transfer function A_iof Shunt series configuration is _________? I_in / I_out -I_out / I_in I_out I_in 〖1+I〗_in / I_out Hint 49). Units of Shunt-series feedback is ____________? Voltage/Amperes Amperes/Amperes Amperes/Voltage Voltage/Voltage Hint 50). Units of Series-shunt feedback system is_____? Volts/Amperes Amperes/Amperes Amperes/Volts Volts/Volts Hint Positive Feedback Amplifier Interview Questions and Answers 51). In Shunt-series feedback system, the series connection at the output _______ , output resistance R_out. Decreases Increases Infinity Constant Hint 52). In Shunt-series feedback system, the shunt connection at the input _______, the input resistance R_in. Decreases Increases Infinity Constant Hint 53). In Shunt-series feedback system, input signal is _____? Current Voltage Inductance Resistance Hint 54). In series-series feedback system, configuration is defined as ________current to the input voltage. Output Input Inverting Non-inverting Hint 55). Series-series feedback system works as a ____________ amplifier. Voltage Current Trans conductance Trans resistance Hint 56). Trans conductance is represented by_____? I_m V_m G_m None of the above Hint 57). Transfer gain of series-series feedback circuit G_m is_____? V_in / I_out I_out / V_in I_out V_in None of the above Hint 58). In Series-series feedback configuration input signal is ______? Voltage Current Trans conductance Trans resistance Hint 59). In Series-series feedback configuration output signal is__________? Voltage Current Trans conductance Trans resistance Hint 60). The ideal output resistance is very ____in series-series feedback. Low Null High Infinity Hint 61). Shunt connection in shunt-series feedback ________ the input resistance. Increases Decreases Inverting Constant Hint Positive Feedback Amplifier MCQs for Exams 62). Shunt-shunt feedback systems also known as ________? Shunt-series feedback Shunt-voltage feedback Series voltage feedback Series current feedback Hint 63). Shunt-shunt feedback systems operates as a ________ feedback system? Voltage-current controlled Current-voltage controlled Voltage-voltage controlled Current-current controlled Hint 64). Transfer gain of shunt-shunt feedback circuit R_m is_____? V_out / I_in I_out / V_in I_out V_in None of the above Hint 65). Shunt voltage configuration works as ______________type. Trans conductance Trans resistance Conductance Amplifier Hint 66). Ideal input resistance of shunt-shunt feedback system then Rin will be ________? Large Small Constant Null Hint 67). In shunt-shunt feedback system, the output _________ is fed back as a current to current driven-port. Inductance Current Voltage Amplifier Hint 68). As ideal input resistance is very small, then the ideal output resistance will also be___? Large Small Constant Null Hint 69).Shunt connections at both input and output terminals reduce the ______impedance. Output Inverting Non-inverting Amplifier Hint 70). Feedback output signal is sampled and fed back to input to form _____ signal. Input Output Error Source Hint 71). Degenerative feedback reduce _________ property. System gain Bandwidth Timing Clock pulse Hint 72). Negative feedback system is used to improve _____ systems stability. Control Impedance Resistance Susceptance Hint 73). Processing of feedback systems ranges from simple to ________ circuits. Simple Complex Easy Infinite Hint 74). Feedback circuit characteristics can be independent of _______? Frequency Operating conditions Wavelength Source Hint 75). Complex digital feedback systems are formed using_____? ICs Transistors Resistors Controllers Hint Read more about Difference between IC and Electronic Devices.. Please fill in the comment box below. Time is Up! Time's up
