*Question E7A11:
What does “positive logic” mean in reference to logic devices?*  

*Correct Answer is  B: High voltage represents a 1, low voltage a 0*  

### AI Response: (may contain errors)  

In the context of logic devices, "positive logic" refers to a system where high voltage levels represent a binary '1' and low voltage levels represent a binary '0'. 

### Correct Answer Explanation:
- **B: High voltage represents a 1, low voltage a 0**  
  This is the definition of positive logic. In this system, when the voltage is above a certain threshold, it is interpreted as a logical '1', and when it is below that threshold, it is interpreted as a logical '0'. This is a standard convention in digital electronics.

### Incorrect Answer Explanations:
- **A: The logic devices have high noise immunity**  
  While many logic devices do have noise immunity, this characteristic is not specifically defined by the term "positive logic." Noise immunity refers to the ability of a circuit to resist interference, which is not inherently tied to whether the logic is positive or negative.

- **C: The logic circuit is in the “true” condition**  
  This statement is vague. While a high voltage (logical '1') can indicate a "true" condition in positive logic, the term "true" does not specifically define what positive logic means. It is more about the representation of voltage levels rather than the state of the circuit.

- **D: 1s and 0s are defined as different positive voltage levels**  
  This statement is misleading. In positive logic, '1' is represented by a high voltage and '0' by a low voltage, but it does not imply that both are "positive" voltage levels. One is high (positive) and the other is low (which could be zero or negative).

### Summary:
- Positive logic is defined by the representation of high voltage as '1' and low voltage as '0'.
- Understanding this concept is crucial for working with digital circuits and logic devices.

### Rule of Thumb:
- In positive logic systems, remember:  
  - High Voltage = 1  
  - Low Voltage = 0