Low Pass Filter Question & Answers February 28, 2022 By WatElectronics This article lists 100 Low Pass Filter (LPF) MCQs for engineering students. All the Low Pass Filter (LPF) 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 their fundamentals on Low Pass Filter (LPF). A filter is an electronic passive device designed to obstruct a few frequencies and allow the required frequency. They are classified into 4 types namely low pass filter, high pass filter, bandpass filter, and band rejected filter. A low pass filter is a device that permits only the lower frequency value signal and blocks high-frequency value signals from it. They are classified into 2 types namely Inductive and capacitive. These filters are designed using 3 main passive components such as a resistor, capacitor, and inductor. LPF can be designed with first order and second order LPF filters wherein first-order LPF only one set of RC circuits is connected with the source and in second-order LPF multiple RC circuits are cascaded. The gain obtained from first-order LPF is about 0.707A. They provide benefits in terms of eliminating the aliasing effect, minimum output impedance, protecting cut-off frequency, etc. The minimum voltage gain value they limit is below one. These filters are deployed in equalizers, speakers, amplifiers, etc. 1). The input frequency applied to low pass filter is ____? High Low Zero Constant None Hint 2). The output frequency obtained from low pass filter is ____? High Low Zero Constant None Hint 3). A device that separates disturbances from a signal is ____? Filter Diode Switch All the above None Hint 4). Which of the following are the applications of filter? Radar TV Control systems All the above None Hint 5). Which of the following are the types of filters? Linear and non-linear Active, passive Analog, digital All the above None Hint 6). _____ parameter of a filter depends on design of filter? Frequency response Voltage Breakdown value All the above None Hint 7). A LPF is also called ____? High cut filter Treble-cut filter Low-cut filter Both a and b None Hint 8). Which of the following are LPF circuits? Hiss filter Anti-aliasing Digital All the above None Hint 9). Which of the following is the application of hiss filter? Audio ADC Image blur All the above None Hint 10). Which of the following is the application of anti-aliasing filter? Audio ADC Image blur All the above None Hint 11). Which of the following is the application of digital filter? Audio ADC Image blur All the above None Hint Read more about Control Systems. 12). A proto-type filter is a _____ filter? Electronic Mechanic Chemical Bio None Hint 13). Which of the following are the types of proto-type filter? LPF BPF BSF All the above None Hint 14). Which of the following are the applications of hiss filter? Acoustics Optics Electronics All the above None Hint 15). Which of the following is the low frequency value? 100 KHz <100KHz >100KHz =1000KHz None Hint 16). Which of the following is the high frequency value? 100 KHz <100KHz >100KHz =1000KHz None Hint 17). Which of the following is the output wave shape obtained from ideal low pass filter? Sine Rectangle Triangle Peak None Hint 18). Which of the following are the components of low frequency type a passive filters? Resistors Capacitors Inductors Both a and b None Hint 19). Which of the following are the components of high frequency type passive filters? Resistors Capacitors Inductors All the above None Hint 20). A circuit design with resistor, capacitor and inductor component is called _____circuit? RLC RC LC RL None Hint 21). A first order LPF filter is called ____ circuit? Integrator Differentiator Multiplier Adder None Hint 22). The components of LPF are connected in _____ configuration? Series Parallel Concurrent Both b and c None Hint 23). Increase in frequency of LPF _____ the gain value? Increases Decreases Zero Constant None Hint 24). The gain in transition band end stage of a LPF is ____? 1 0 Infinity Constant None Hint 25). The BW of LPF is ____? High Low Zero Limited None Hint Low Pass Filter Interview Questions and Answers 26). At which of the following component of LPF input is applied? Resistor Capacitor Inductor Load None Hint 27). At which of the following component of LPF output is obtained? Resistor Capacitor Inductor Load None Hint 28). A capacitor has ___ number of parallel plates? 1 2 3 4 None Hint 29). An LPF first order filter are classified in to ___ number of types? 1 2 3 4 None Hint 30). Which of the following are the components of LPF inductive type circuit? Resistor Inductor Capacitor Both a and b None Hint 31). Which of the following are the components of LPF capacitive type circuit? Resistor Inductor Capacitor Both a and c None Hint 32). Increase in input frequency of LPF inductive type circuit ____ the value of inductors impedance? Increases Decreases Zero Constant None Hint 33). Which of the following is the advantage of Inductive based LPF? Blocks high frequency Allows low frequency Generates constant frequency Both a and b None Hint 34). A capacitive type LPF is also called ___? Simple LPF Dual LPF Harmonic LPF All the above None Hint 35). Increases in input signal ____ the impedance of capacitor? Increases Decreases Zero Infinity None Hint 36). Which of the following are the components of second order LPF? Resistor Capacitor Inductor All the above None Hint 37). The output from second order LPF is taken from ___ component? Resistor Capacitor Inductor All the above None Hint 38). Which of the following are passive components in second order LPF responsible for blocking high frequency? Resistor Capacitor Inductor Both b and c None Hint 39). A LPF designed with an OP-amp is ____ type of LPF? Active Passive Zero Both a and b None Hint 40). Which of the following is the function of op-amp in op-amp LPF? Signal amplification Gain control Noise free Both a and b None Hint 41). An OP-amp LPF has _____ input impedance? High Low Zero Constant None Hint 42). An OP-amp LPF has _____ output impedance? High Low Zero Constant None Hint 43). An op-amp LPF has _____ noise? High Low Zero Constant None Hint 44). An op-amp LPF has _____ performance level? High Low Zero Constant None Hint 45). Op-amp in op-amp LPF is connected to ___ components terminal? Resistors Capacitors Inductors Both b and c None Hint 46). An op-amp poses ____ type of characteristics? Linear Non-linear Zero Constant None Hint 47). An op-amp has ___ number of terminals? 2 3 4 5 None Hint 48). An inverted terminal in op-amp is called ____? Positive Negative Zero Both b and c None Hint 49). An non-inverted terminal in op-amp is called ____? Positive Negative Zero Both b and c None Hint 50). The output amplitude obtained from RC low pass is _____ the amplitude of input signal in first order op-amp LPF? Large Small Zero Infinity None Hint Low Pass Filter Quiz Questions and Answers. 51). The power gain of LPF op-amp is ____ in first order op-amp LPF? Large Small Zero Infinity None Hint 52). The stability of LPF op-amp is ____ in first order op-amp LPF? Large Small Zero Infinity None Hint 53). OP-amp with LPF acts as___ circuit? Buffer Voltage follower Current follower Both a and b None Hint Read more about Voltage Follower. 54). The DC gain of OP-amp with LPF is ____ in first order op-amp LPF? =1 >1 <1 0 None Hint 55). At which frequency value, RC circuit signal flow via op-amp for amplification in first order op-amp LPF? Low High Zero Constant None Hint 56). Which of the following is voltage gain of first order op-amp LPF? 1/R1+R2 R1+R2 1/R1-R2 R1* R2 None Hint 57). How many RC filters are cascaded in second order LPF? 1 2 3 4 None Hint 58). Op-amp in second order LPF acts as ___? Voltage controlled source amplifier Current controlled source amplifier Resistance controlled source amplifier Capacitance controlled source amplifier None Hint 59). The band gain of second order LPF is ____ times the first order LPF? 2 3 4 5 None Hint 60). Which of the following is the value of second order active LPF op-amp band gain? 40 dB/decade 50 dB/decade 60 dB/decade 70 dB/decade None Hint 61). Cascading of multiple filter circuits is ____ order type filter? High Low Constant Zero None Hint 62). Which of the following is the gain value of first order LPF active filter at cut-off frequency? -3dB -4dB -5dB -6dB None Hint 63). Which of the following is the gain value of second order LPF active filter at cut-off frequency? -3dB -4dB -5dB -6dB None Hint 64). The value of gain of first order filter is ___ times the second order LPF gain? 2 3 4 5 None Hint 65). Which of the following is the formula of gain of second order active LPF? Av1*Av2 Av1+Av2 Av1-Av2 Av1/Av2 None Hint 66). Which of the following is the formula of total gain of second order active LPF? Av1*Av2 Av1+Av2 Av1-Av2 Av1/Av2 None Hint 67). Gain is expressed in terms of ___ units? dB Hertz Baud rate Both b and c None Hint 68). A LPF calculator is used for calculating ____ LPF circuit parameters? Cut-off frequency Voltage gain Phase shift All the above None Hint 69). Which of the following is the transfer function equation of second order LPF filter? H(s)=Vo(s)/Vi(s) H(s)=Vi(s)/Vo(s) H(s)=1/(1+sCR) Both a and c None Hint 70). Which of the formula of ‘s’ in transfer function? jw j/w w/j w-j None Hint 71). The value of transfer function of second order LPF filter when w=0 is_________? 1 0 Constant Infinity None Hint 72). Which of the following is the value of transfer function of second order LPF filter when w=1/CR? 0.707 0 0.1 0.5 None Hint 73). Which of the following is the value of transfer function of second order LPF filter when w=infinity? 0.707 0 0.1 0.5 None Hint 74). Which of the following is the gain of transfer function of second order LPF filter in frequency domain? 1/sqt[1+(w/wc)^2] 1/[1+(w/wc)^2] 1/sqt[1-(w/wc)^2] 1/sqt[1+(w/wc)^3] None Hint 75). Which of the following is the total gain of transfer function of second order LPF filter in frequency domain? 20log10(Vout/Vin) 20log10(Vin/Vout) 20log10(Vout+Vin) 20log10(Vout-Vin) None Hint Low Pass Filter MCQs for Exams 76). Which of the following is the phase shift formula of LPF? tan-1 [w/wc] Sin-1[w/wc] Cos [w/wc] Tan[w/wc] None Hint 77). Which of the following is the cut off frequency of LPF? 1/2πRC 2πRC 1/πRC 1/4πRC None Hint 78). Which of the following is the phase shift formula in RC format of LPF? tan-1[2 πRC] tan-1[1/2 πRC] tan-1[1/ πRC] tan-1[1-2 πRC] None Hint 79). Which of the following is the capacitive reactance formula of LPF? 1/2 πRC 1-2 πRC 1+2 πRC 1/ πRC None Hint 80). Frequency is expressed in terms of ___ units? Hertz Volts Amperes Henry None Hint 81). Increase in frequency of LPF, the output voltage _____ the input voltage? <70% >70% =70% Both a and b None Hint 82). A device that measures amplitude of a frequency component is ____? Wave analyzer Signal analyzer Carrier frequency voltmeter All the above None Hint Read more Wave Analyser 83). Which of the following is the frequency of wave analyzer? 50MHz 10MHZ 100MHz 110MHz None Hint 84). Which off the following are the components of wave analyzer? LPF Primary detector Full wave rectifier All the above None Hint Read more about Full Wave Rectifier. 85). A device that increases the amplitude of a signal is called ___? Amplifier Rectifier Tuner Oscillator None Hint 86). Which of the following are the major component amplifiers? FET BJT CMOS Both a and b None Hint 87). FET stands for ___? Field Effect Transistor Fine Effect Transistor Field Elevate Transistor Field Effect Type None Hint Read more about FET. 88). A BJT has ___ number of terminals? 1 2 3 4 None Hint 89). A DC value current is ____ dimensional? 1D 2D 3D 4D None Hint 90). A DC value flows through which of the following substances? Conductor Insulators Semiconductor All the above None Hint 91). The characteristics of a LPF are plotted on _____ dimension? 1 2 3 4 None Hint 92). Which of the following parameter of LPF characteristics is plotted on X-axis? Gain Angular frequency Voltage Current None Hint 93). Which of the following parameter of LPF characteristics is plotted on Y-axis? Gain Angular frequency Voltage Current None Hint 94). A cut-off frequency is also called ____? Corner frequency Break frequency Highest frequency Both a and b None Hint 95). A bandwidth consists of which of the following frequencies? Higher frequency Lower frequency Mid frequency All the above None Hint 96). A frequency response of a signal is a measurement of ____ ? System spectrum System input Characteristic Both a and b None Hint 97). ____ type of filter can be used as audio and feedback systems? Analog Digital Both a and b None of the above None Hint 98). A resistor has ___ number of terminals? 1 2 3 4 None Hint 99). Which of the following is the function of a resistor? Minimize current flow Remove transmission lines Bias active elements All the above None Hint 100). Resistors are elements of ____? Electrical networks Electronic circuits Mechanical devices Both a and b None Hint Please fill in the comment box below. Time's up