Question

pls answer this question

Answer 1

1)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.

2)Electrical resistivity the resistance across a current carrying conductor.
The reading of the ammeter doubles when the length of the length of the wire is halved as lenght as the resistance (R) is directly proportional to the length of the wire. When the length increases the resistance also decreases and the current increases and hence the reading of the ammeter doubles when the the wire is halved