Answer & Solution
Answer: Option A
Solution:
Transformer coupling is commonly used in power amplifiers because it offers several advantages:
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Impedance Matching: Transformers can efficiently match the high output impedance of the power amplifier to the low impedance of the loudspeaker.
This maximizes
power transfer to the load (speaker).
*
DC Isolation: Transformers provide
DC isolation between the amplifier stage and the load.
*
Efficiency: Although transformers can introduce some losses, they generally offer better efficiency in impedance matching compared to other coupling methods for power amplifiers.
Let's look at why the other options are less suitable for power amplifiers:
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RC Coupling: While simple and inexpensive,
RC coupling suffers from significant power loss and poor impedance matching, making it less suitable for power amplifiers where efficiency is crucial.
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Direct Coupling: Direct coupling can be challenging due to DC offset issues and the potential for damaging the loudspeaker with DC current.
*
Impedance Coupling: While impedance coupling can refer to using inductors or tuned circuits, it's not as widely used as transformer coupling in general power amplifier designs, especially for audio frequencies and can be complex.
