Physics

Problem

Two identical conducting spheres are separated in space. Sphere A initially has a charge of

+6.0\,\mu\text{C}

, and Sphere B has a charge of

-2.0\,\mu\text{C}

. The spheres are briefly connected by a conducting wire and then separated again. Approximately how many electrons moved from one sphere to the other during the connection? a)

1.3\times10^{13}

4.0\times10^{13}

2.5\times10^{13}

2.5\times10^{12}

Intuitive explanation

When two identical conducting spheres touch, charge redistributes until both reach the same potential—which means they end up sharing the total charge equally. The key is to find how much charge actually moved, then convert that to a number of electrons using the elementary charge. Think of it as a charge-balancing act: calculate the final charge on each sphere, figure out how much one sphere gained or lost, and divide by the charge of a single electron.

Intuitive explanation

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