*Question E7G10:
What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1,800 ohms and RF is 68 kilohms?*  

*Correct Answer is  C: 38*  

### AI Response: (may contain errors)  

To determine the absolute voltage gain of the circuit in Figure E7-3, we need to understand that this is a typical inverting amplifier configuration using an operational amplifier (op-amp). The voltage gain ($A_v$) for an inverting op-amp is given by the formula:

$$
A_v = -\frac{R_F}{R_1}
$$

where:
- $R_F$ is the feedback resistor,
- $R_1$ is the input resistor.

Given:
- $R_1 = 1,800 \, \text{ohms}$
- $R_F = 68,000 \, \text{ohms}$ (68 kilohms)

Substitute these values into the formula:

$$
A_v = -\frac{68,000}{1,800} \approx -37.78
$$

The absolute value of the voltage gain is approximately 38. Therefore, the correct answer is **C: 38**.

### Explanation of Choices:
- **A: 1**  
  This would imply no gain, which is incorrect for the given resistor values.
  
- **B: 0.03**  
  This suggests a very low gain, which is not possible with the given resistor values.
  
- **C: 38**  
  This is correct as calculated above, representing the absolute value of the gain.
  
- **D: 76**  
  This would imply a much higher gain than calculated, which is incorrect.

### Key Points:
- The negative sign in the gain formula indicates phase inversion, but the question asks for absolute gain, so we consider only the magnitude.
- The gain is determined by the ratio of the feedback resistor to the input resistor in an inverting op-amp configuration.