What operational improvements result from negative feedback_______________?
Show answer Hide answer
Answer: B. increases the input impedance and bandwidth
Explanation
Applying negative feedback in series input configurations increases the overall input impedance significantly. Negative feedback also extends the usable frequency bandwidth by lowering closed loop gain peaks. This combination of higher input impedance and wider bandwidth improves overall amplifier performance. Input impedance represents the opposition presented to incoming voltage or current signal sources. Bandwidth refers to the range of frequencies over which the amplifier maintains specified performance. Series negative feedback samples output voltage and returns a proportional voltage in series with the input.
Higher input impedance prevents the amplifier from loading down delicate voltage source transducers. Wider bandwidth ensures faithful reproduction of high speed pulses and complex audio signals. Engineers use negative feedback to tailor amplifier characteristics for specific instrumentation needs. Option A is incorrect because output impedance typically decreases with voltage negative feedback. Option C incorrectly claims bandwidth decreases when negative feedback actually broadens the frequency response. Option D is wrong because negative feedback dramatically alters both impedance and bandwidth.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. What energy conversion does an electronic oscillator perform __________?
Show answer Hide answer
Answer: B. power into a.c. power
Electronic oscillators draw direct current electrical power from an external battery or power supply. Internal circuit action converts this steady DC input into periodic alternating current output waveforms. Active devic...
Q2. Reducing the resistance values in the positive feedback loop of a Wien-bridge oscillator causes its frequency to____________?
Show answer Hide answer
Answer: C. Increases
The oscillation frequency of a Wien bridge oscillator is inversely proportional to the resistance values. Reducing the resistance values in the frequency determining network decreases the time constant of the circuit. A...
Q3. What components dictate the operating frequency of a phase-shift oscillator _______________?
Show answer Hide answer
Answer: C. R and C
Phase shift oscillators rely exclusively on resistors and capacitors within their feedback networks. The specific values of these resistors and capacitors determine the exact operating frequency of the circuit. Inductors...
Q4. Which frequency range cannot be generated using an LC oscillator____________?
Show answer Hide answer
Answer: C. Very low
LC oscillators use inductors and capacitors to establish the resonant operating frequency. Generating very low frequencies requires impractically large inductance and capacitance component values. Physically massive indu...
Q5. Why are quartz crystals predominantly chosen for crystal oscillator designs:____________?
Show answer Hide answer
Answer: A. It has superior electrical properties
Quartz crystals are chosen for oscillators because of their exceptional electrical properties and stability. The mechanical resilience and low thermal expansion of quartz provide unmatched frequency stability. These supe...
Q6. How is common-mode voltage gain defined________________?
Show answer Hide answer
Answer: A. smaller than differentail voltage gain
Common mode voltage gain is intentionally designed to be much smaller than differential voltage gain. Low common mode gain ensures that noise signals appearing equally on both inputs are heavily suppressed. Maximizing di...