What is the function of a bypass capacitor in a BJT amplifier circuit?
Practice Questions
Q1
What is the function of a bypass capacitor in a BJT amplifier circuit?
To increase the gain
To stabilize the bias point
To filter out noise
To provide AC coupling
Questions & Step-by-Step Solutions
What is the function of a bypass capacitor in a BJT amplifier circuit?
Step 1: Understand what a BJT amplifier is. A BJT (Bipolar Junction Transistor) amplifier is a circuit that amplifies weak electrical signals.
Step 2: Identify the role of the emitter resistor in the BJT amplifier. The emitter resistor helps stabilize the amplifier and sets the gain.
Step 3: Learn about AC and DC signals. AC (Alternating Current) signals vary over time, while DC (Direct Current) signals are constant.
Step 4: Recognize that the gain of the amplifier can be affected by the emitter resistor when dealing with AC signals.
Step 5: Understand what a bypass capacitor does. A bypass capacitor is connected in parallel with the emitter resistor.
Step 6: Realize that the bypass capacitor provides a low impedance path for AC signals. This means AC signals can pass through it easily.
Step 7: Conclude that by bypassing the emitter resistor for AC signals, the gain of the amplifier is increased because the resistor does not affect the AC signals as much.
