My question is 1. can we use 1 poe switch as power supply for another layer 2/3 switch? 2. If question 1's answer is yes then What should be maximum distance between those? As per my reading in various websites, distance not more than 1000meter... Can we use poe for 2km any how? means distance between 2 switches is 2km.
Ethernet copper cable max distance is 100m. Over this distance you must switch (sic) to another technology. Cheap DSL converters or fiber optic, depending on the budget, existing wires...
And yes you can power one switch with POE from another... but check their respective power requirement and delivery.
Yes, but you'll need a switch like the HP 1810-8G in between.