Consider a coin of exercise 1.20. It is electrically neutral and contains equal amounts positive and negative charge of magnitude 34.8 kC. Suppose that these equal charges were concentrated in two point charges separated by (i) 1 cm (~half the diagonal of one paisa coin) (ii) 100 m (~length of a long building), and (iii) `10^6` m (radius of the earth). Find the force on each such point charge in each of the three cases. What do you conclude from these results?

Explanation

To solve the problem, we will use Coulomb's Law, which states that the force \( F \) between two point charges \( q_1 \) and \( q_2 \) separated by a distance \( r \) is given by:

\[ F = \frac{1}{4 \pi \epsilon_0} \frac{q_1 q_2}{r^2} \]

In this case, since both charges are equal in magnitude and opposite in sign, we can denote them as \( q = 34.8 \, \text{kC} = 3.48 \times 10^4 \, \text{C} \).

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