Electronic Devices And Circuits Set 10
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This set of Electronic Devices and Circuits Multiple Choice Questions & Answers (MCQs) focuses on Electronic Devices And Circuits Set 10
Q1 | The output of a class-B amplifier
- is distortion free
- consists of positive half cycle only
- is like the output of a full wave rectifier
- comprises short duration current pulses
Q2 | Crossover distortion occurs in amplifiers.
- push-pull
- class a
- class b
- class ab
Q3 | The main use of a class C amplifier is
- as an rf amplifier
- as stereo amplifier
- in communication sound equipment
- as distortion generator
Q4 | The decibel is a measure of
- power
- voltage
- current
- sound level
Q5 | The output stage of a multistage amplifier is also called
- mixer stage
- power stage
- detector stage
- f stage
Q6 | coupling is generally employed in power amplifiers
- transformer
- rc
- direct
- impedance
Q7 | The maximum efficiency of resistance loaded class A power amplifier is
- 5%
- 50%
- 30%
- 25%
Q8 | Class power amplifier has the highest collector efficiency
- c
- a
- b
- ab
Q9 | Power amplifiers handle signals compare to voltage amplifiers.
- small
- very small
- large
- none of the above
Q10 | In class B operation, at what fraction of VCC should the level of VL(p) be to achieve the maximum power dissipated by the output transistor?
- 0.5
- 0.636
- 0.707
- 1
Q11 | In class A operation, the operating point is generally located of the d.c. load line.
- at cut off point
- at the middle
- at saturation point
- none of the above
Q12 | The output transformer used in a power amplifier is a transformer.
- 1:1 ratio
- step-up
- step-down
- none of the above
Q13 | Power amplifiers primarily provide sufficient power to an output load, typically from to .
- a few kw, tens of kw
- 500 w, 1 kw
- 100 w, 500 w
- a few w, tens of w
Q14 | The main feature(s) of a large-signal amplifier is (are) the .
- circuit\s power efficiency
- maximum amount of power that the circuit is capable of handling
- impedance matching to the output
- all of the above
Q15 | In power amplifiers, the output signal varies for a full 360º of the cycle.
- class a
- class b or ab
- class c
- class d
Q16 | In class B power amplifiers, the output signal varies for of the cycle.
- 360º
- 180º
- between 180º and 360º
- less than 180º
Q17 | amplifiers have the highest overall efficiency.
- class a
- class b or ab
- class c
- class d
Q18 | Class D operation can achieve power efficiency of over .
- 90%
- 78.50%
- 50%
- 25%
Q19 | The beta of a power transistor is generally .
- more than 200
- 100 to 200
- less than 100
Q20 | A form of class A amplifier having maximum efficiency of _ uses a transformer to couple the output signal to the load.
- 90%
- 78.50%
- 50%
- 25%
Q21 | The reflected impedance seen from one side of the transformer to the other side is .
- n1/n2
- (n1/n2)2
- (n1/n2)1/3
- n1× n2
Q22 | In a class A transformer-coupled power amplifier, winding resistance of the transformer determine(s) the dc load line for the circuit.
- the ac
- the dc
- both the ac and dc
- neither the ac nor dc
Q23 | The slope of the ac load line in the class A transformer-coupled transistor is .
- –1/rl (load resistor)
- 1/(a2rl)
- –1/(a2rl)
- 1/rl
Q24 | The amount of power dissipated by the transistor is the of that drawn from the dc supply (set by the bias point) and the amount delivered to the ac load.
- product
- difference
- average
Q25 | A class A amplifier dissipates power when the load is drawing maximum power from the circuit.
- the least
- about the same
- the most
- none of the above