Hawkins Electrical Guide v. 01 (of 10) / Questions, Answers, & Illustrations, A progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications

by N. Hawkins

For instance, 2 amperes in ¹⁄₂ hour, or 4 amperes in ¹⁄₄ hour will also give one ampere-hour of 3,600 coulombs.

It is well to keep the distinction between coulombs and amperes in mind, as even in text books very lately published these units are confounded. To illustrate further the difference between coulombs and amperes, the following example is given.

It is sometimes estimated that the quantity of electricity in a flash of lightning is ¹⁄₁₀ coulomb, and the duration of the discharge ¹⁄₂₀₀₀₀ part of a second. What is the current in amperes?

Now since

coulombs = amperes × seconds (1)

solving (1) for the current,

amperes = coulombs/seconds (2)

substituting the given values in (2),

amperes = (¹⁄₁₀) / (¹⁄₂₀₀₀₀) = 2000