Amplifiers

1. 1. What do you call an amplifier which has an output current flowing during the whole input current cycle?1. class AB amplifier1. class B amplifier1. class A amplifier1. class C amplifier

1. Class A amplifier can be built from what transistor configuration?1. common base1. common emitter1. common collector1. all of the above

1. If a transistor amplifier provides a 360 output signal, it is classified as1. class A1. class B1. class C1. class D

1. An amplifier that delivers an output signal of 180 only.1. class A1. class B1. class AB1. class D

1. A class of amplifiers wherein the output signal swings more than 180 but less than 360.1. class A1. class B1. class C1. class AB

1. What is the distinguishing feature of a class C amplifier?1. Output is present for less than 180 degrees of the input signal cycle1. Output is present for the entire signal cycle1. Output is present for exactly 180 degrees of the input signal cycle1. Output is present for more than 180 degrees but less than 60 degrees of the input signal cycle

1. A full 360 sine-wave signal is applied as an input to an unknown class of amplifier, if the output delivers only a pulse of less than 180, of what class does this amplifier belongs?1. class AB1. class B1. class C1. class D

1. Which class of amplifiers that is intended for pulse operation?1. class B1. class C1. class D1. class S

1. How do you classify an amplifier used to amplify either amplitude modulated (AM) or frequency modulated (FM) signals?1. class C1. class BC1. class D1. class S

1. Which class of an amplifier that has the highest efficiency?1. class A1. class B1. class C1. class D

1. What is the efficiency of a series-fed class A amplifier?1. 25%1. 50%1. 78.5%1. above 90%

1. A class A amplifier has an efficiency of only 25%, but this can be increased if the output is coupled with a transformer. Up to how much is its efficiency will reach due to coupling?1. 36.5%1. 50%1. 68.5%1. 78.5%

1. Class B amplifiers deliver an output signal of 180 and have a maximum efficiency of1. 50%1. 68.5%1. 78.551. above 90%

1. Transistorized class C power amplifiers will usually have an efficiency of1. 25%1. 33%1. 50%1. 78.5%

1. For pulse-amplification, class D amplifier is mostly used. How efficient is a class D amplifier?1. about 25% efficient1. less efficient than class B1. more efficient than class A but less efficient than class B1. its efficiency reaches over 90%

1. An amplifier of class AB means its output signal is between the output of class B and A, such that it varies from 180 (class B) to 360 (class A). How about its efficiency?1. Efficiency of class AB is in between the efficiency of class A and B, that is from 25% - 78.5%.1. It is always as efficient as class A (25%).1. It is always as efficient as class B (78.5%)1. The efficiency of class AB is the average of the efficiencies of both class A and class B (25% + 78.5%)/2 = 51.75%

1. Among the given amplifiers below, which is the most efficient?1. class A (series-fed)1. class A (transformer-coupled)1. class A (directly-coupled)1. class A (capacitor-coupled)

1. In order to have the best efficiency and stability, where at the loadline should a solid state power amplifier be operated?1. Just below the saturation point1. At 1.414 times the saturation point1. Just above the saturation point1. At the saturation point

1. In most transistor class A amplifiers, the quiescent point is set at1. near saturation1. near cutoff1. below cutoff1. at the center

1. For a class B amplifier, the operating point or Q-point is set at1. the top of the load line1. saturation1. the center1. cutoff

1. The Q-point for class A amplifier is at the active region, while for class B it is at cutoff region, how about for class AB?1. it is slightly below saturation1. it is slightly above cutoff1. it is slightly above saturation1. it is at the saturation region

1. Where does the Q-point of a class C amplifier positioned?1. at saturation region1. at active region1. at cutoff region1. below cutoff region

1. The Q-point of a class D amplifier can be set or positioned at what region in the load line?1. below saturation1. above cutoff1. at cutoff1. any of the above

1. Which of the amplifiers given below that is considered as non-linear?1. class A1. class B1. class AB1. class C

1. Which amplifiers can be used for linear amplification?1. class A 1. class B1. class C1. class A or B

1. What do you call an amplifier that is biased to class C but modulates over the same portion of the curve as if it were biased to class B?1. class S1. class D1. class AB1. class BC

1. Two class B amplifiers connected such that one amplifies the positive cycle and the other amplifies the remaining negative cycle. Both output signals are then coupled by a transformer to the load.1. transformer-coupled push pull amplifier1. complementary-symmetry amplifier1. quasi-complementary push-pull amplifier1. transformer-coupled class A amplifier

1. A push-pull amplifier that uses npn and pnp transistors to amplify the positive and negative cycles respectively.1. transformer-coupled push pull amplifier1. complementary-symmetry amplifier1. quasi-complementary push-pull amplifier1. transformer-coupled class A amplifier

1. A push-pull amplifier that uses either npn or pnp as its final stage. The circuit configuration looks like the complementary-symmetry.1. transformer-coupled push pull amplifier1. complementary-symmetry amplifier1. quasi-complementary push-pull amplifier1. feed-back pair amplifier

1. Amplifiers conversion efficiency are calculated using what formula?1. ac-power/dc-power1. ac-power/dissipated power1. dc-power/ac-power1. A or B are correct

1. Basically, which class of amplifiers has the least distortion?1. class A1. class B1. class C1. class D

1. A type of distortion wherein the output signal does not have the desired linear relation to the input.1. linear distortion1. nonlinear distortion1. cross-over distortion1. all of the above

1. Distortion that is due to the inability of an amplifier to amplify equally well all the frequencies present at the input signal.1. nonlinear distortion1. amplitude distortion1. harmonic distortion1. cross-over distortion

1. A nonlinear distortion in which the output consists of undesired harmonic frequencies of the input signal.1. amplitude distortion1. frequency distortion1. cross-over distortion1. harmonic distortion

1. Calculate the 2nd harmonic distortion for an output signal having a fundamental amplitude of 3V and a 2nd harmonic amplitude of 0.3V.1. 1.0%1. 10%1. 23.33%1. 43.33%

1. An amplifier has the following percent harmonic distortions; D2=10%, D3=5% and D4=1%. What is the amplifier % THD?1. 5.33%1. 11.22%1. 16.0%1. 22.11%

1. Which of the following refers to the gain of a circuit?1. Input quantity of an amplifier divided by the output quantity.1. The difference between the input voltage and the output voltage of a circuit.1. The ratio of the output quantity to input quantity of an amplifier.1. The total increase in output quality over the input quantity of an amplifier.

1. The overall gain of an amplifier in cascade is1. the sum1. the average of each1. the product1. 100% the sum

1. If three amplifiers with a gain of 8 each are in cascade, how much is the overall gain?1. 721. 241. 5121. 8

1. A multistage transistor amplifier arranged in a conventional series manner, the output of one stage is forward-coupled to the next stage.1. cascaded amplifier1. cascoded amplifier1. darlington configuration1. feed-back pair configuration

1. A direct-coupled two-stage transistor configuration wherein the output of the firs transistor is directly coupled and amplified by the second transistor. This configuration gives a very high current gain.1. cascade configuration1. cascode configuration1. darlington configuration1. feed-back pair

1. A two-stage transistor amplifier in which the output collector of the first stage provides input to the emitter of the second stage. The final output is then taken from the collector of the second stage.1. cascade configuration1. cascode configuration1. quasi-complementary1. complementary amplifier

1. Famous transistor amplifier configuration designed to eliminate the so called Miller effect.1. cascode amplifier1. darlington amplifier1. differential amplifier1. complementary-symmetry

1. What are the transistor configurations used in a cascade amplifier?1. common-base and common-emitter1. common-base and common-collector1. common-collector and common-emitter1. common-emitter and common-base

1. Transistor configuration known to have a super-beta (2).1. cascade1. cascode1. darlington1. differential

1. What is the approximate threshold voltage between the base-emitter junction of a silicon darlington transistor?1. 0.3 V1. 0.6 V1. 1.6 V1. 3.0 V

1. Transistor arrangement that operates like a darlington but uses a combination of pnp and npn transistors instead of both npn.1. differential1. common1. cascode1. feedback pair

1. An amplifier basically constructed from two transistors and whose output is proportional to the difference between the voltages applied to its two inputs.1. differential amplifier1. cascode amplifier1. complementary amplifier1. quasi-complementary amplifier

1. An amplifier having high direct-current stability and high immunity to oscillation, this is initially used to perform analog-computer functions such as summing and integrating.1. operational amplifier (op-amp)1. parametric amplifier (par-amp)1. instrumentation amplifier1. DC-amplifier

1. One of the most versatile and widely used electronic device in linear applications.1. SCR1. FET1. UJT1. op-amp

1. It is a very high-gain differential amplifier with very high input impedance and very low output impedance.1. par-amp1. op-amp1. differential amp1. complementary amp

1. What are the possible applications of operational amplifiers (op-amps)?1. ac and dc-amplifiers1. oscillators and signal conditioning1. voltage-level detectors and comparators1. all of the above

1. An operational amplifier must have at least how many usable terminals?1. 3 terminals1. 5 terminals1. 8 terminals1. 14 terminals

1. The circuit at the input stage of operational amplifiers1. differential amplifier1. cascaded amplifier1. current mirror1. complementary amplifier

1. An amplifier whose output is proportional to the difference between the voltages applied to its two inputs.1. differential amplifier1. differencing1. delta amp1. cascode-amp

1. In op-amps functional block diagram, what follows the differential amplifier?1. cascode-amplifier1. complementary amplifier1. level shifter1. high gain amplifier

1. A good op-amp has a1. very high input resistance1. very low input resistance1. very high output resistance1. very low CMRR

1. Ideally, op-amps have infinite input resistance and ________ output resistance.1. infinite1. zero1. variable1. a highly stabilized

1. How does the input of an op-amp made high?1. by using super beta transistor at the input differential stage1. by using FETs at the input differential stage1. by connecting a very high resistance in series with the input differential stage1. A and B above

1. What type of amplifier commonly used at the output stage of op-amps?1. differential amplifier1. cascade-amplifier1. complementary amplifier1. darlington stage amplifier

1. The transistor configuration used at the output complementary stage of most op-amps1. cascode configuration1. common emitter1. common collector1. common base