Electronic Devices And Circuits Set 11
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This set of Electronic Devices and Circuits Multiple Choice Questions & Answers (MCQs) focuses on Electronic Devices And Circuits Set 11
Q1 | In a class A transformer-coupled amplifier, the the value of VCEmax and the the value of VCEmin, the the efficiency to (from) the theoretical limit of 50%.
- larger, smaller, farther
- larger, smaller, closer
- smaller, larger, closer
- none of the above
Q2 | In class B operation, the current drawn from a single power supply has the form of rectified signal.
- a full-wave
- a half-wave
- both a full-wave and a half-wave
- none of the above
Q3 | The highest efficiency is obtained in class B operation when the level of VL(p) is equal to .
- 0.25vcc
- 0.50vcc
- vcc
- 2vcc
Q4 | transistors can be used to build a class B amplifier.
- npn and pnp
- nmos and pmos
- both npn and pnp or nmos and pmos
- none of the above
Q5 | The complementary Darlington-connected transistor for a class B amplifier provides output current and output resistance.
- higher, higher
- higher, lower
- lower, lower
- lower, higher
Q6 | The fundamental component is typically any harmonic component.
- larger than
- the same as
- smaller than
- none of the above
Q7 | In Fourier technique, any periodic distorted waveform can be represented by the fundamental and all harmonic components.
- multiplying
- subtracting
- dividing
- adding
Q8 | Improvement in production techniques of power transistors have .
- produced higher power ratings in small-sized packaging cases
- increased the maximum transistor breakdown voltage
- provided faster- switching power transistors
- all of the above
Q9 | The greater the power handled by the power transistor, the
- the higher
- the lower
- there is no
- none of the above
Q10 | The has the hottest temperature in a power transistor.
- heat sink
- case
- junction
- none of the above
Q11 | A heat sink provides thermal resistance between case and air.
- a high
- a low
- the same
- none of the above
Q12 | A power amplifier is limited to use at one fixed frequency.
- class a
- class b or ab
- class c
- class d
Q13 | By how much does the output signal vary for a class AB power amplifier?
- 360º
- 180º
- between 180º and 360º
- less than 180º
Q14 | Which type of amplifier uses pulse (digital) signals in its operation?
- class a
- class b or ab
- class c
- class d
Q15 | Which of the power amplifiers has the lowest overall efficiency?
- class a
- class b or ab
- class c
- class d
Q16 | Which of the following describe(s) a power amplifier?
- it can handle large power.
- it can handle large current.
- it does not provide much voltage gain.
- all of the above
Q17 | amplifiers primarily provide sufficient power to an output load to drive a speaker from a few watts to tens of watts.
- small-signal
- power
- none of the above
- all of the above
Q18 | The main features of a large-signal amplifier is the circuit's .
- power efficiency
- maximum power limitations
- impedance matching to the output device
- all of the above
Q19 | Categorize the power efficiency of each class of amplifier, from worst to best.
- a, b, ab, d
- a, ab, d, b
- a, ab, b, d
Q20 | What is the ratio of the secondary voltage to the primary voltage with the turn ratio in the winding
- n2/n1
- (n1/n2)2
- (n1/n2)1/3
- n1 × n2
Q21 | Calculate the effective resistance seen looking into the primary of a 20:1 transformer connected to an 8- Ω load.
- 3.2 kΩ
- 3.0 kΩ
- 2.8 kΩ
- 1.8 kΩ
Q22 | What transformer turns ratio is required to match an 8-speaker load so that the effective load resistance seen at the primary is 12.8 k?
- 20:01
- 40:01:00
- 50:01:00
- 60:01:00
Q23 | Calculate the efficiency of a transformer-coupled class A amplifier for a supply of 15 V and an output of V(p) = 10 V.
- 25%
- 33.30%
- 50%
- 78.50%
Q24 | The maximum efficiency of a transformer-coupled class A amplifier is .
- 25%
- 50%
- 78.5%
- 63.6%
Q25 | How many transistors must be used in a class B power amplifier to obtain the output for the full cycle of the signal?
- 0
- 1
- 2
- 3