Bipolar Junction Transistors (BJT) Questions

• A transistor used in a digital circuit will have two operating states, which are cutoff and saturation.
• BJTs are "junction" transistors because they use current-carrying P-N junctions.
• The voltage measured from the collector to the emitter is the sum of the voltage base-emitter plus the voltage collector-base.
• Current gain in a transistor is inversely proportional to collector current.
• The three bipolar transistor circuit configurations are common-base, common-emitter, and emitter-follower.
• When a transistor is operating as a variable resistor it has transistance.
• The polarity of VBE is such that it reverse biases the base-emitter junction.
• The voltage gain of a transistor is inversely proportional to the change in output current.
• This is a PNP transistor.
• The voltage measured from the collector to the emitter is the sum of the base-emitter voltage plus the collector-base voltage.
• In a BJT, the collector current is approximately equal to the base current.
• When troubleshooting a bipolar junction transistor using an ohmmeter, if one of the junctions reads low in both directions, the junction is shorted and the transistor is bad. If one of the junctions reads high in both directions, the junction is shorted and the transistor is good.
• Base bias provides _________.
• The signal voltage gain of an amplifier, AV, is defined as __________.
• The input resistance, Rin of a common-collector amplifier, consists of ____________.
• VCE approximately equals ________ when a transistor switch is in saturation.
• An emitter-follower has a voltage gain that is __________.
• VCE approximately equals ________ when a transistor switch is cut off.
• The phase difference between the input and output ac voltage signals of a common-emitter amplifier is __________.
• The input resistance of the base of an emitter-follower is usually _________.