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• 1. Amplifier Basics
• 2. Class A Amplifier Design
• 3. Multistage Amps & NFB
• 4. Amplifier Circuits
• 5. Power Amplifiers
• 6. Operational Amplifiers

Module 4.4

Amplifier Circuits Quiz

Try our quiz, based on the information you can find in Amplifiers Module 4. Submit your answers and see how many you get right. If you get any answers wrong. Just follow the hints to find the right answer and learn about Amplifiers as you go.

1.

What would be the function of the control circuit shown in Fig. 4.4.1 in an audio amplifier?

• a) Volume.
• b) Balance.
• c) Treble boost.
• d) Tone.

2.

What is the purpose of RIAA de-emphasis in an audio pre-amplifier?

• a) To provide correct impedance matching on a MIC input.
• b) To provide D to A conversion on a CD input.
• c) To provide frequency correction on a PHONO input.
• d) To provide level correction on a line level output.

3.

When the bass and treble controls in a Baxandall passive tone control circuit are set at their mid point, what will be the approximate voltage gain of the tone control circuit?

• a) -3dB
• b) -6dB
• c) -20dB
• d) -40dB

4.

Complete the following sentence: Compared with a bipolar transistor, using a JFET transistor in the input stage of an audio amplifier instead of a bipolar transistor provides...

• a) ...higher input impedance and reduced signal to noise ratio.
• b) ...higher input impedance and increased signal to noise ratio.
• c) ...higher gain and increased signal to noise ratio.
• d) ...higher gain and reduced signal to noise ratio.

5.

Bootstrapping in an amplifier circuit refers to which of the following techniques?

• a) Using positive feedback to increase the apparent input impedance of the amplifier.
• b) Using negative feedback to increase the apparent input impedance of the amplifier.
• c) Using negative feedback to reduce the apparent output impedance of the amplifier.
• d) Using positive feedback to increase the stability of the amplifier.

6.

Which of the following features does the circuit illustrated in Fig. 4.4.2 posess?

• a) High voltage gain and very high input impedance.
• b) Low voltage gain and very high output impedance.
• c) High current gain and very high input impedance.
• d) Low current gain and very high output impedance.

7.

Which of the following would be a typical value for the input impedance of a common collector amplifier?

• a) 1KΩ
• b) 15KΩ
• c) 150KΩ
• d) 15MΩ

8.

Refer to Fig 4.4.3. If the real value of R3 is 33KΩ and the open loop gain of the emitter follower amplifier (A_O) is 0.98, what will be the apparent value R3?

• a) 1.65MΩ
• b) 2.35MΩ
• c) 3.27MΩ
• d) 230.5KΩ

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