Figure $18

Question

Figure $18 < 1$ -If $\mathrm { R } _ { f } = 1.2 \mathrm { M } \Omega$ and A_V=120 in Figure 18-1( c), Ri equals___________ A) 1 $\mathrm { k } \Omega$ B) 10 $\mathrm { k } \Omega$ C) 120 $\Omega$ D) 100 $\mathrm { k } \Omega$

Quizplus · Accepted Answer

Given that $A_V = 120$ and $\mathrm { R } _ { f } = 1.2 \mathrm { M } \Omega$, the formula to find $R_i$ when dealing with operational amplifiers and feedback resistors typically involves the gain and the feedback resistor. The gain is given as 120, and the feedback resistor is $1.2 \mathrm { M } \Omega$. The input resistance $R_i$ can be calculated by dividing the feedback resistance by the gain, which gives $R_i = \frac{1.2 \mathrm { M } \Omega}{120} = 10 \mathrm { k } \Omega$.

Figure 18<118 < 118<1 -If Rf=1.2MΩ\mathrm { R } _ { f } = 1.2 \mathrm { M } \OmegaRf​=1.2MΩ

Figure $18 < 1$ -If $\mathrm { R } _ { f } = 1.2 \mathrm { M } \Omega$