There is only one ActiveCell, not one per sheet. (Actually, there's one per
window, but I assume you don't have more than one window.)

You could activate the different sheets and make a reference  to their
individual active cells, then use those references later.

What are you trying to achieve?

I want to get value of any cell lets say B5 in sheet4
My active sheet  is sheet1.

You cannot use the reference  as Activecell. value instead use

Sheets("Sheetname").Cells(Row No , Column No). Value.

Example :

Sheets("Sales"),cells(1,1).Value (Refers to Sales!$a$1)