If a three-stage electronic amplifier features individual stage gains of 10 dB, 5 dB, and 12 dB, what is the total cumulative gain in dB____________?
Show answer Hide answer
Answer: D. 27 db
Explanation
Total gain in decibels for cascaded amplifier stages is found by taking the direct algebraic sum of the individual stage decibel gains. Decibel units represent logarithmic power ratios, allowing engineers to add stage gains together rather than multiplying linear voltage ratios. Summing the individual decibel values of ten, five, and twelve yields a cumulative total gain of exactly twenty-seven decibels. Cascaded electronic amplifiers connect multiple stages in series to achieve higher overall signal gain than any single stage provides. The decibel scale compresses large multiplication factors into manageable additive numbers, simplifying cascade system analysis and design. Logarithmic math rules dictate that multiplying linear gains corresponds directly to adding their logarithmic decibel equivalents together.
Six hundred decibels is mathematically incorrect and represents an extreme exaggeration resulting from improper multiplication instead of addition. Twenty-four decibels is an incorrect arithmetic sum of the provided stage values due to calculation errors in addition. Fourteen decibels fails to account for the correct cumulative addition of all three positive amplifier stage gain values.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. For which of the following metallurgical processes are induction furnaces deployed ?
Show answer Hide answer
Answer: A. Heat treatment of castings
Induction furnaces are widely used in foundries for heat treatment, melting, and metallurgical processing of metals. The rapid generation of internal eddy currents provides precise and uniform volumetric heating ideal fo...
Q2. If RC and RL denote the collector resistance and external load resistance in a single-stage transistor amplifier, what constitutes the total AC load____________________?
Show answer Hide answer
Answer: B. RC || RL
The total AC load impedance seen by a single-stage amplifier collector is the parallel combination of the collector resistor and the external load resistor. AC coupling capacitors connect the collector to the external lo...
Q3. When the air gap between a capacitor's plates is replaced by a solid dielectric material_____________?
Show answer Hide answer
Answer: C. The potential difference decreases but both capacitance and energy increase
Inserting a solid dielectric into a capacitor increases capacitance and energy storage while lowering the potential difference under constant charge. Dielectric materials polarize in electric fields, effectively reducing...
Q4. If a transistor amplifier is biased such that output current flows for only 60° of the input cycle, what class of operation is this ______________?
Show answer Hide answer
Answer: C. Class C
In class C operation, the active device conducts for substantially less than 180 degrees of the input cycle, typically around 60 degrees. Conduction angles shorter than a half-cycle characterize Class C amplifiers, which...
Q5. What type of signal distortion is indicated if a transistor amplifier's gain-versus-frequency response curve is not flat ?
Show answer Hide answer
Answer: C. Frequency
Variations in gain across different frequencies indicate frequency distortion caused by reactive components in the amplifier circuit. Capacitors and inductors introduce reactance that alters gain magnitudes at very low a...
Q6. If a transistor amplifier draws 2 mA of current when presented with a 10 V input voltage, what is its input impedance ____________?
Show answer Hide answer
Answer: D. 5 kΩ
Input impedance is calculated by dividing the input voltage by the input current (10 volts divided by 2 milliamperes equals 5 kiloohms). Ohm's law applies directly to the input terminals of an amplifier when determining...