Question

(b) Why
are +/- sign marked at the terminals of an ammeter and a voltmeter ?​

Answer 1

Answer:

If a voltmeter is connected in series with a source or load, it will measure the source voltage, but no current will flow and the circuit will not operate. The +/- terminals of either meter just indicate the direction of current or voltage with respect to the meter terminal labels.

Answer 2

They show the direction in which positive charge will flow and the negative charge.

(+) mark show the positive charge and ( -) show

the negative charge..