🔍 Key Concepts

• Bias voltage in a vacuum tube and how it sets the operating point (no-signal plate current) • Relationship between bias, grid signal magnitude, and whether you want to avoid or allow grid current • How permissible plate dissipation, distortion limits, and desired amplification influence tube operating conditions

💭 Think About

• Ask yourself: Which option(s) directly relate to how you choose the tube’s quiescent (idle) operating point on its characteristic curves? • Consider whether class of operation (Class A, B, AB, etc.) and plate supply voltage by themselves set the bias, or if they only influence where you might choose to bias the tube. • Think about whether bias voltage is chosen mainly from what you want at no-signal conditions (idle current, grid current) or from signal conditions like maximum output power.

✅ Before You Answer

• Check which choices involve idle/no-signal conditions (like no-signal plate current and grid current) rather than only signal conditions. • Verify which listed factors you would actually use when plotting a load line and picking a bias point on the tube curves. • Be sure that any factor you include must have a direct effect on the required DC grid bias, not just on general amplifier performance.