Question

The Bode diagram stability criterion is applicable when:

• A. gain and phase curves both decrease with frequency
• B. gain curve increases and phase curve decreases with frequency
• C. gain curve decreases and phase curve increases with frequency
• D. gain and phase curves both increase with frequency

Hint:

In Bode stability analysis, gain and phase both typically decrease with increasing frequency.

Answer 1

The Correct Option is A

Step 1: Bode criterion.
In Bode stability analysis, stability margin is determined from the frequency response where both gain and phase generally decrease with frequency.

Step 2: Option check.
- (A) Correct: Applicable when both decrease. - (B), (C), (D): Do not reflect the typical behavior required for Bode stability analysis.

Final Answer: \[ \boxed{\text{A) gain and phase curves both decrease with frequency}} \]