In Coulomb's law, 'e' represents the elementary charge (also known as the electronic charge), which is the magnitude of the electric charge carried by a single proton or electron.
Here's a breakdown:
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Definition: 'e' is a fundamental physical constant representing the basic unit of electric charge.
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Value: Its approximate value is 1.602 × 10-19 Coulombs (C).
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Role in Coulomb's Law: While 'e' doesn't explicitly appear in the standard formula of Coulomb's Law (F = k |q1 q2| / r²), it's crucial for understanding the quantization of charge. The charges (q1 and q2) in Coulomb's law are often multiples of the elementary charge 'e'. In other words, the charge of an object is typically an integer multiple of 'e'.
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Example: An ion with a charge of +2e has a charge of +2 * (1.602 × 10-19 C) = +3.204 × 10-19 C.
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Why it's important: The concept of elementary charge is key to understanding that electric charge is not infinitely divisible; it comes in discrete packets, the smallest of which is 'e'.
In essence, while you might not directly see 'e' in the simplified Coulomb's law equation, it's fundamental because the q values themselves are usually understood in terms of multiples of this fundamental charge unit.
