Isolation,and it blocks DC Voltage
yes, diode can be used as rectifier diode to convert ac to dc
A diode is used primarily as a Rectifier
A PLC is programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes.
yes ofcourse diode can be used as rectifier but it's an uncontrolled rectification.
varactor diode is a correct answer
zener diode
It's a high voltage diode, typically used in microwave ovens.
The difference between the pn-junction diode and the zener diode is that the pn-junction diode is used for rectification while the zener diode is used for rectification and stabilization. Also, the zener diode can function in the breakdown region while the pn-juntion diode can not function in that regime.
A zener diode cannot be used as switch.
The use of the pn diode is for rectification. It can also be used as a switch.
A Photo-diode is used to receive light. whereas the L.E.D. is a Light Emitting Diode.
zener diode is a revers bias diode which used for voltage regulation.