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.
A time period, denoted by T, is the time taken for one complete vibration (or oscillation or cycle). It is measured in seconds. Frequency, denoted by f, is the number of vibrations (or oscillation or cycle) in 1 second ie number of periods per second. As such, t is measured in s^-1. The relationship between frequency and time is f= 1/T