No. A diode is not like a transistor, and a transistor is not like (two) diode(s). Taken in isolation, the emitter-base and collector-base junctions of a transistor appear to be diodes, but they are coupled together so that the base-emitter current affects the collector-emitter current.
A transistor is a switch. A diode directs the flow of current.
uni junction transistor
A: Actually a transistor have two diode with the base mas a common terminal. the characteristics of these tow diodes however are not the same as a common diode
its the simplest thing to do. There are three legs in a transistor, one each of collector, base and emitter. So if you need to use it as a diode, just connect either collector-base or emitter-base. Say, if you use an NPN transistor, then the base region will be the anode of diode and emitter or collector will be the cathode of the diode.
transistor//
The transistor acts like a normal pn diode. in NPN transistor the both n i.e.,collector and emitter ane shorted then they become a n and other is p so pn diode is formed. When the emitter and the collector of a transistor are short, the emitter current =the collector current.
Transistor will be in OFF mode.
Transistor will be in OFF mode.
Transistor will be in OFF mode.
A transistor is not a diode. It is also not a pair of back to back diodes. Two diodes connected back to back will not function like a transistor because their junctions are not in close proximity like they are in a transistor. The only reason for "thinking" that a transistor is "like" a pair of back to back diodes is for purposes of quick go-nogo testing with a multimeter, but that will only assess open, short, and leakage status, as well as polarity, but not any of the more useful things, such as hFe.
A: Yes it can but why ? This is frequently done when the diode is used for biasing purposes on another transistor and must be matched identically to the transistor's E-B junction characteristics. Thus 2 matched transistors are used with one just being used as a diode.
photo diode donot work for long distance photo diode act as a receiver