Transistor failure can occur due to a variety of reason. The following are some of them.
Age
Aging of transistor due to temperature variations inside the components due to carrying current can cause failure. The electrical properties of the materials inside can drift due to age.
External Causes
External causes such as spikes in the power supply, heat, mechanical damage can also result in transistor failures. Hence, all transistors should be adequately protected against overvoltage.
Poor Circuit design.
Improperly chosen components and wrong circuit design can also result in transistor failure. Hence, all components in the circuit should be properly rated with sufficient allowance for overloading and temperature rise. The failure of one component can lead to cascade failures of other components.
Overheating
Overheating is the most common cause of transistor failure. Hence, it is important that transistors be provided with cooling mechanism. Devices which contain temperature-sensitive electronic components should be kept in air conditioned environments.
Electrostatic Discharge
Electrostatic discharge can also damage transistors. Hence proper precautions against Electrostatic Discharge Should be taken.
current carriers
If the EBJ is forward baise and the CBJ is reverse baised then the transistor will in the active/forward mode of operation.
Reverse-biased ---from the book of Malvino
The input of a transistor is typically referred to as the "gate" in a field-effect transistor (FET) or the "base" in a bipolar junction transistor (BJT). In both cases, the input controls the flow of current through the transistor, allowing it to function as a switch or amplifier in electronic circuits. The gate or base receives the input signal that modulates the transistor's operation.
False. For normal operation, an NPN transistor will have the base be more positive than the emitter and less positive than the collector, with the collector more positive than the emitter. Whether the base is grounded or not depends on the chosen design configuration of the circuit.
Very nonlinear. If you need operation approximatinglinearity, a transistor must be limited to a very narrow range of operation.
In class c operation, the transistor conducts 100% of the time.
current carriers
Emitter-Base junction should be forward biased.Collector-Base junction should be reverse biased.
If the EBJ is forward baise and the CBJ is reverse baised then the transistor will in the active/forward mode of operation.
We bias transistors in order to determine the modes of operation ( that is whether the transistor is operating in the active cut off or the saturation regions).
Reverse-biased ---from the book of Malvino
The input of a transistor is typically referred to as the "gate" in a field-effect transistor (FET) or the "base" in a bipolar junction transistor (BJT). In both cases, the input controls the flow of current through the transistor, allowing it to function as a switch or amplifier in electronic circuits. The gate or base receives the input signal that modulates the transistor's operation.
A: An operating in biasing is determined by the transistor capabilities as a linear amplifier. Basically it is a bias to insure linear operation with the loading of the output
That depends on whether you are considering conventional current or electron current.
A load line is used in graphic analysis of circuits, having both linear and non-linear parts, representing the constraint the other parts of the circuit put on the non-linear transistor. It represents the response of the linear circuit connected to the transistor. The DC load line describes the DC operation of a transistor graphically.
False. For normal operation, an NPN transistor will have the base be more positive than the emitter and less positive than the collector, with the collector more positive than the emitter. Whether the base is grounded or not depends on the chosen design configuration of the circuit.