ok example heat isn't problem .
electricity what problem is ? only limit kw ?
Heat most certainly IS a problem. You will not be able to dissipate the heat that 50 miners will generate - especially in an apartment. You also will not be able to provide enough electricity to power those 50 miners.
Please stop asking the same questions repeatedly.
Lets say 50 miners and 340 watts each. Were talking 17k watts of electricity. Most likely your apartment cannot even handle this amount. That is a lot off electricity.
Even if it did the amount of heat during summer is going to be intense. You need lots of gear to keep this amount cool. It will be a battle.