Transistors

In a voltage divider-biased npn transistor, if the upper voltage divider resistor

the transistor goes into cutoff

The approximate voltage across the forward-biased base emitter junction of a silicon on BJT is

0.7V

If the output of a transistor amplifier is 5V rms and the input is 100 mV rms, the voltage gain is

50

The three terminals of a bipolar junction transistor

Base, emitter, collector

Collector feedback bias is

Based on the principle of negative feedback

The input resistance at the base of a biased transistor depends mainly on

Bdc and Re

If a sinusoidal voltage is applied to the base of a biased npn transistor and the resulting sinusoidal collector voltage is clipped near zero volts, the transistor is

Being driven into cut off and operating nonlinearly.

Voltage divider bias

Can be essentially independent of Bdc

The Bdc of a transistor is its

Current gain

In a pnp transistor, the p-region are

Emitter, collector

Emitter bias is

Essentially independent of Bdc and provides a stable bias point

The bias condition for a transistor to be used as linear amplifier is called

Forward-reverse

The emitter current is always

Greater than the base and collector current

To saturate a BJT

Ib > Ic(sat)/ Bdc

In cutoff, Vce is

Maximum and equal to Vcc

In saturation, Vce is

Minimum

Once in saturation, a further increase in base current will

Not affect the collector current

Formula of voltage gain

Output voltage / input voltage

For operation of an amplifier, the base of a npn transistor must be

Positive with respect to the emitter

If the base-emitter junction is open, the collector voltage

Vcc

If the base-emitter junction is open, the collector voltage is

Vcc

Ideally, a dc load line is a straight line drawn on the collector characteristics curves between

Vce(cut off) and Ice(sat)

When operated in cutoff and saturation, the transistor acts like

a switch