There is a fruit battery and several wires. The positive and negative poles of the fruit battery are unknown. Which of the following devices can be used to judge the positive and negative poles () of
There is a fruit battery and several wires. The positive and negative poles of the fruit battery are unknown. Which of the following devices can be used to judge the positive and negative poles () of a fruit battery?
A. voltmeter B. ammeter
Both are fine, but try to get in touch. If the positive and negative poles are connected correctly, the pointer will shift to the right. If the polarity is reversed, the pointer will deflect to the left.