Transistor Audio Power Amplifier Question & Answers July 7, 2021 By WatElectronics This article lists 100 Transistor Audio Power Amplifiers MCQs for engineering students. All the Transistor Audio Power Amplifiers Questions & Answers given below includes solution and link wherever possible to the relevant topic. A power amplifier is one of the blocks just before an antenna on a transmit chain. If you are building a transistor then you will have some RF signals and then you will apply the RF signals to the power amplifier. The requirement of the power amplifier is basically to pump out as much energy as possible through the antenna and broadcast the message. Power amplifiers give high output power, in multistage amplifiers the initial and intermediate stages are small-signal amplifiers or voltage amplifiers, whereas the final or the output stage drives the devices like CRT, transducer, servomotor. The small-signal amplifier amplifies the voltage, and the large-signal amplifier amplifies power or voltage. The power amplifiers have three stages they are voltage amplification stage, output stage, and driver stage. The maximum power capability, efficiency, impedance matching to the output device are the main factors in large-signal amplifiers. The gain, linearity, amplification are the main factors in small-signal amplifiers. Direct and RC coupling, LC coupling, Transformer coupling are the most commonly used transistor amplifier couplings. The coupling capacitors, inductors, and transformer components cause low-frequency gain. 1). The multistage amplifier output stage is called a ________ stage Mixer Power Either a or b None of the above None Hint 2). How many transistors do class A amplifiers use? One Two Three Four None Hint 3). The resistance load class A power amplifier maximum efficiency is _________ 10% 5% 2% 25% None Hint 4). The transistor coupled class A power amplifier maximum efficiency is _________ 10% 50% 2% 25% None Hint 5). Which class amplifier has the highest collector efficiency? Class A Class B Class C Class AB None Hint 6). When compare to voltage amplifiers the power amplifiers handle ___________ Large signals Small signals Very small signals None of the above None Hint 7). __________ amplifier is used to raise the power level of weak signal Power Voltage Both a and b None of the above None Hint 8). __________ amplifier is used to raise voltage level of weak signal Power Voltage Both a and b None of the above None Hint 9). The size of transistor used in voltage amplifier is _____________ Small Very large Large None of the above None Hint 10). The size of the power transistor used in the power amplifier is _____________ Small Very small Large None of the above None Hint 11). In which amplifier heat sinks are used? Power Voltage Both a and b None of the above None Hint 12). ___________ coupling is used in power amplifier Transformer LC RC None of the above None Hint 13). ___________ coupling is used in the voltage amplifier Transformer LC RC None of the above None Hint 14). Which amplifier is used as the first stage of an amplifier? Power Voltage Both a and b None of the above None Hint 15). _________ amplifier is used as the last stage of an amplifier Power Voltage Both a and b None of the above None Hint 16). The output impedance in the power amplifier is ______ High Low Remains constant Very high None Hint 17). The output impedance in the voltage amplifier is ______ High Low Remains constant Very low None Hint 18). The amplifiers are categorized into ________ One Two Three Four None Hint 19). _________ are the limitations of conventional BJT and JFET’s Current<0.8 Voltage<100v Temperature<150 degree Celsius All of the above None Hint 20). The power amplifiers are categorized into __________ One Two Six Four None Hint 21). The class A power amplifiers are categorized into __________ One Two Six Four None Hint 22). The class B power amplifiers are categorized into __________ One Two Six Four None Hint 23). The class A power amplifiers have _________ Less power Less efficiency Less harmonic distortion All of the above None Hint 24). The class B power amplifiers have _________ More power More efficiency More harmonic distortion All of the above None Hint 25). The heat sinks are categorized into __________ One Two Six Four None Hint 26). The advantages of tuned amplifiers are ___________ Small power loss Harmonic distortion is very small Selectivity is high All of the above None Hint Transistor Audio Power Amplifier MCQs for Quiz 27). The tuned amplifiers used in __________ I.F amplifiers RF amplifiers Radar amplifiers All of the above None Hint 28).The single tuned amplifiers are categorized into _____________ One Two Six Four None Hint 29). In large signal tuned amplifiers ___________ Output power is more Operated in class B, C, or AB modes To amplify large RF signals All of the above None Hint 30). In small signal tuned amplifiers ___________ Output power is low Operated in class A mode To amplify low RF signals All of the above None Hint 31). The distortion in audio amplifiers and another type of circuits depends on __________ Source resistance, bias condition Input signal level, loading effect Type of output load and its impedance All of the above None Hint 32). The audio power amplifier used in _________ Television set Smartphone Music system All of the above None Hint 33). The conduction angle for class A power amplifier is _________ 90 deg 180 deg 360 deg None of the above None Hint 34). The conduction angle for the class B power amplifier is _________ 90 deg 180 deg 360 deg None of the above None Hint 35). The conduction angle for class C power amplifier is _________ <90 deg 180 deg 360 deg None of the above None Hint 36). The conduction angle for the class AB power amplifier is _________ <90 deg 180 deg 180 to 360 deg None of the above None Hint 37). The position of the Q-point in class A amplifier is _________ Centre point of the load line Exactly on X-axis Below the X-axis In between X-axis and the center load line None Hint 38). The position of the Q-point in class B amplifier is _________ Centre point of the load line Exactly on X-axis Below the X-axis In between X-axis and the center load line None Hint 39). The position of the Q-point in class C amplifier is _________ Centre point of the load line Exactly on X-axis Below the X-axis In between X-axis and the center load line None Hint 40). The position of the Q-point in class AB amplifier is _________ Centre point of the load line Exactly on X-axis Below the X-axis In between X-axis and the center load line None Hint 41). The overall efficiency of the class A amplifier is _________ 25%-30% 2%-30% 1%-30% None of the above None Hint 42). The overall efficiency of the class B amplifier is _________ 25%-30% 70%-80% 1%-30% None of the above None Hint 43). The overall efficiency of the class C amplifier is _________ 25%-30% 70%-80% >80% None of the above None Hint 44). The overall efficiency of the class AB amplifier is _________ 25%-30% 70%-80% 50%-70% None of the above None Hint 45). The IC LM386 is a ___________ audio amplifier Low power High power Low voltage High voltage None Hint 46). Lm386 is a ___________ pin IC Two Six Eight Four None Hint 47). The advantages of class D amplifier are _________ Efficiency is high At high frequency, the switching distortion is minimal Both a and b None of the above None Hint 48). The disadvantages of class D amplifier are _________ Expensive Requires a large number of elements Power losses can occur All of the above None Hint 49). The advantages of class AB amplifier are _________ Efficiency is high Quiescent current is low Signal distortion is low All of the above None Hint 50). The ratio of power delivery to the load divided by DC power take from the supply is known as ________ Amplifier efficiency Amplifier gain Gain None of the above None Hint Transistor Audio Power Amplifier MCQs for Exams 51). The power gain of the amplifier expressed in ___________ Decibels Ohms Volts None of the above None Hint 52). The product of voltage gain and current gain is known as _________ Power gain Amplifier efficiency Current gain None of the above None Hint 53). The voltage gain in dB is equal to __________ 20 log Av 20 log Ai 20 log Ap None of the above None Hint 54). The current gain in dB is equal to __________ 20 log Av 20 log Ai 20 log Ap None of the above None Hint 55). The power gain in dB is equal to __________ 20 log Av 20 log Ai 20 log Ap None of the above None Hint 56). The amplifier gains are of ________ types One Two Three Four None Hint 57). The ratio of output voltage divided by input voltage is known as _____ Voltage gain Current gain Power gain None of the above None Hint 58).- The ratio of output current divided by input current is known as _____ Voltage gain Current gain Power gain None of the above None Hint 59). In which amplifier both current and voltage can be amplified? Voltage Current Power None of the above None Hint Read more about Amplifier 60). In common emitter, the input signal is applied to ___________ Base Ground Emitter None of the above None Hint 61). In common collector, the input signal is applied to ___________ Base Ground Emitter None of the above None Hint 62). In common base, the input signal is applied to ___________ Base Ground Emitter None of the above None Hint 63). In common emitter, the output signal is taken from the ____________ Base Ground Emitter Collector None Hint 64). In common collector, the output signal is taken from the ____________ Base Ground Emitter Collector None Hint 65). In common base the output signal is taken from the ____________ Base Ground Emitter Collector None Hint 66). The common emitter sometimes called the ___________ Grounded emitter Grounded collector Grounded base None of the above None Hint 67). The common collector sometimes called the ___________ Grounded emitter Grounded collector Grounded base None of the above None Hint 68). The common base sometimes called the ___________ Grounded emitter Grounded collector Grounded base None of the above None Hint 69). In __________ the common line is connected to the emitter Common emitter Common collector Common base None of the above None Hint 70). In __________ the common line is connected to the collector Common emitter Common collector Common base None of the above None Hint 71). In __________ the common line is connected to the base Common emitter Common collector Common base None of the above None Hint 72). For circuit isolation and impedance matching __________ coupling is used LC, RC Direct Transformer All of the above None Hint 73). _____________ components cause low frequency gain loss in a cascade amplifier Coupling capacitors Inductors and transformers Both a and b None of the above None Hint 74). ___________ is the most commonly used transistor amplifier coupling Direct and RC coupling LC coupling Transformer coupling All of the above None Hint 75). ___________ are the main factors in small-signal amplifiers Gain Linearity Amplification All of the above None Hint Transistor Audio Power Amplifier Important MCQs 76). ___________ are the main factors in large-signal amplifiers Maximum power capability Efficiency Impedance matching to the output device All of the above None Hint 77). What is the unit of power dissipation? Decibels Watts Henry None of the above None Hint 78). The output is proportional to the input in _________ amplifier operation Linear Non-linear Both a and b None of the above None Hint 79). ____________ are the properties of an ideal amplifier Input resistance Gain Output resistance All of the above None Hint 80). In class A amplifier the conduction angle ϴ is equal to __________ 2π π < π None of the above None Hint 81). The output is not proportional to the input in _________ amplifier operation Linear Non-linear Both a and b None of the above None Hint 82). In class B amplifier the conduction angle ϴ is equal to __________ 2π π < π None of the above None Hint 83). In class C amplifier the conduction angle ϴ is equal to __________ 2π π < π None of the above None Hint 84). The power efficiency in the class A amplifier is ______ Good Very good Poor Fair None Hint 85). The power efficiency in the class B amplifier is ______ Good Very good Poor Fair None Hint 86). The power efficiency in the class AB amplifier is ______ Good Very good Poor Fair None Hint 87). The power efficiency in the class C amplifier is ______ Good Very good Poor Fair None Hint 88). The power efficiency in the class D amplifier is ______ Good Very good Poor Fair None Hint 89)._________ are the disadvantages of transformer coupled class A amplifier Frequency response is poor Transformers are costly and bulky Both a and b None of the above None Hint 90). The advantage of transformer-coupled class A amplifier are ___________ Gain is high DC isolation is provided Both a and b None of the above None Hint 91). The power amplifiers has _________ stages One Two Three Four None Hint 92). In ________ amplifier, power transistors are required Large signal Small signal Both a and b None of the above None Hint 93). __________ amplifier amplifies voltage Large signal Small signal Both a and b None of the above None Hint 94). __________ amplifier amplifies power or voltage Large signal Small signal Both a and b None of the above None Hint 95). Which amplifier is bulky? Large signal Small signal Both a and b None of the above None Hint 96).The power amplifier invented in __________ 2000 1890 1990 1909 None Hint 97). Who invented a power amplifier? Lee De Forest Marcian Hoff Stanley Mazor None of the above None Hint Read more about Amplifier 98). _______ are the features of power amplifier Impedance matching with load Capable of handling large power Power transistor is required All of the above None Hint 99). The transistor in class A power amplifier conducts for ______ duration Full cycle Half cycle Both a and b None of the above None Hint 100). In __________ power amplifier the power dissipation is between class A and B operation Class A Class B Class AB None of the above None Hint Time's up
