In 1919, the 18th Amendment to the U.S. Constitution, which prohibited the sale and manufacture of alcohol, was ratified. It went into effect on January 16, 1920âbeginning the era known as Prohibition.
Because time constant calculations are important, and often needed, it is better to make the definition of the time constant (T) in a CR circuit: THE TIME TAKEN FOR THE VOLTAGE ACROSS A CAPACITOR TO INCREASE BY 63.2% OF THE DIFFERENCE BETWEEN ITS PRESENT AND FINAL VALUES.
The time constant for an inductor-resistor circuit is calculated by L/R. Once again, we can see that the units for the ratio of these variables-t/(L/R) - is dimensionless. L is measured in Henrys = wb/amp. Resistance is measured in ohms = volt/amp.