ECET 205 Chapter 8: Basic BJT Amplifiers

For DC, the current in a coupling circuit is:

Zero

The current in a coupling circuit for high frequencies is:

Maximum

A coupling capacitor is:

A DC open and an AC short.

In a bypass circuit, the top of a capacitor is:

An AC Ground.

The capacitor that produces an AC ground is called a:

Bypass Capacitor

The capacitors of a CE amplifier appear to be:

Shorted to AC

Reducing all DC sources to zero is one of the steps in getting the:

AC Equivalent Circuit

The AC equivalent circuit is derived from the original circuit by shorting all:

Capacitors

When the AC base voltage is too large, the AC emitter current is:

Distorted

In a CE amplifier with a large input signal, the positive half-cycle of the AC emitter current is:

Larger than the negative half-cycle.

The AC emitter resistance equals 25 mV divided by the:

DC Emitter Current

To reduce the distortion in a CE amplifier, reduce the:

AC Base Voltage

If the AC voltage across the emitter diode is 1 mV and the AC emitter current is 100 muA, the AC resistance of the emitter diode is:

10 Ohms

A graph of the AC emitter current v.s AC base-emitter voltage applies to the:

Emitter Diode

The output voltage of a CE amplifier is:

All of the above.

The emitter of a CE amplifier has no AC voltage because of the:

Bypass Capacitor

The voltage across the load resistor of a capacitor-coupled CE amplifier is:

AC Only

The AC collector current is approximately equal to the:

AC Emitter Current

The AC emitter current multiplied by the AC emitter resistance equals the:

AC Base Voltage

The AC collector current equals the AC base current multiplied by the:

AC Current Gain

When the emitter resistance RE doubles, the AC emitter resistance:

Increases

The emitter is at AC ground in a:

CE Stage

The output voltage of an emitter-bypassed CE stage is usually:

Dependent on r’e

The input impedance of the base decreases when:

Beta Decreases

Voltage gain is directly proportional to:

AC Collector Resistance

Compared to the AC resistance of the emitter diode, the feedback resistance of a swamped amplifier should be:

Large

Compared to a CE stage, a swamped amplifier has an input impedance that is:

Larger

To reduce the distortion of an amplified signal, you can increase the:

Emitter Feedback Resistance

The emitter of a swamped amplifier:

Has an AC voltage.

A swamped amplifier uses:

Negative Feedback

The feedback resistor:

Reduces Distortion

The feedback resistor also:

Stabilizes Voltage Gain

If the emitter-bypass capacitor opens, the AC output voltage will:

Decrease

If the load resistance is open, the AC output voltage will:

Increase

If the output-coupling capacitor is open, the AC input voltage will:

Remain The Same

If the emitter resistor is open, the AC input voltage at the base will:

Increase

If the collector resistor is open, the AC input voltage at the base will:

Decrease