Question

define ideal restance of ameter and voltmeter

Answer 1

Just like voltmeters, ammeters tend to influence the amount of current in the circuits they're connected to. However, unlike the ideal voltmeter, the ideal ammeter has zero internalresistance, so as to drop as little voltage as possible as electrons flow through it.

Answer 2

the internal resistance of an ideal voltmeter is infinity and the internal resistance of an ideal ammeter is 0.