An amplifier has a power gain of 100. Its db gain is ___________

Answer: Option B

The gain in decibels (dB) is a way to express the ratio of two power levels on a logarithmic scale.
The formula to convert power gain to dB gain is:
dB gain = 10 * log10 (Power Gain)
In this question, the power gain is 100.
So, dB gain = 10 * log10 (100)
Since 100 is 10 squared (10^2), log10 (100) is 2.
Therefore, dB gain = 10 * 2 = 20 dB.
So, a power gain of 100 corresponds to a dB gain of 20 dB.