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In a neon discharge tube, 2.9 × 10¹⁸ Ne+ ions cross a given cross-section each second toward the right, and at the same time 1.2 × 10¹⁸ electrons cross the same section each second toward the left. If the electronic charge is 1.6 × 10⁻¹⁹ C, what is the resulting electric current?

1. 0.27 A toward the right
2. 0.66 A toward the right
3. 0.66 A toward the left
4. 0 A

Correct answer: 0.66 A toward the right

Solution

The resulting electric current is calculated by considering the contributions from both the Ne+ ions and the electrons. The current due to the Ne+ ions is positive as they move to the right, while the current due to the electrons moving to the left is negative. The net current is the sum of these two contributions, resulting in a total of 0.66 A toward the right.

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