Question

which of the following device has the highest resistance ammeter,voltmeter,rheostat,key

Answer 1

ammeter has highest resistance i hope you are interested

Answer 2

An ammeter is an instrument for measuring the electric current in amperes in a branch of an electric circuit. It must be placed in series with the measured branch, and must have very low resistance to avoid significant alteration of the current it is to measure. By contrast, an voltmeter must be connected in parallel.