Question

A galvanometer shows deflection when current enters through either of its terminal, though in opposite directions. An ammeter and a voltmeter are nothing but a galvanometer with a suitable resistance connected to it parallel and series respectively. Yet ammeter and voltmeter work only when current enters the positive terminal. Why? How is it decided that which terminal will be positive and which one negative?

Answer 1

Positive and negative signs are given as according to Potential ,The terminal having high Potential is termed as Positive and one having low Potential is termed as negative terminal.And the dierection of Current is always from positive to negative(High to low potential region).