Question

An amplifier has a voltage gain of $100$. The voltage gain in $dB$ is

• A. $20\, dB$
• B. $40\, dB$
• C. $30 \,dB$
• D. $50\, dB$

Answer 1

Answer: (B)

$40\, dB$

Answer 2

Voltage gain in $dB = 20\,log_{10}A_V$ $= 20\,log_{10} 100$ $= 20\times 2$ $= 40\, dB$