1.As the saying goes,"the opposite sex attracts one another",and this is also true of dealing with electric charges.
2.No matter which random resistor you test,the voltmeter will always read 3V.
3.The sine wave decribes that the voltage and the electric current will go up and down with the passing of time in an AC circuit.
4.Metal has a weak resistance,but a large electric current will still pass it through.
5.People found there are repulsive force and attraction between electric charges,though this force is weak.
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