Question

The voltage gain of the following amplifier is

• A. 10
• B. 100
• C. 1000
• D. 9.9

Answer 1

Answer: (B)

Voltage gain of the given operational amplifier is defined as ratio of output voltage to input voltage.
$A_V=\frac{V_o}{V_i}$
From ohm's law $V=iR$, where $i$ is current, $R$ is resistance.
$\therefore A_V=\frac{R_f}{R_i}=\frac{100k\Omega }{1k\Omega }=100$