Question

In the formula TC x R = C, where TC represents the time constant in seconds, R represents the resistance in ohms, and C represents the capacitance in farads, a capacitor will charge to about 63 percent of the supply voltage in one time constant, and reach its full charge in about five time constants. What is the purpose of the time constant (TC) in this context?

Option 1: To determine the supply voltage for the capacitor.
Option 2: To calculate the resistance of the capacitor.
Option 3: To quantify the time required for the capacitor to reach its full charge.
Option 4: To measure the capacitance of the capacitor.

Answer 1

The time constant (TC) in an RC circuit is used to quantify the time required for a capacitor to charge to about 63 percent of the supply voltage in one time constant, and to almost full charge in about five time constants.

Step-by-step explanation:

The purpose of the time constant (TC) in the context of an RC circuit is to quantify the time required for a capacitor to charge and discharge. In the formula TC x R = C, where TC represents the time constant in seconds, R represents the resistance in ohms, and C represents the capacitance in farads, the time constant is a crucial factor that determines how quickly a capacitor can reach a certain percentage of its full charge. A capacitor will charge to approximately 63 percent of the supply voltage in one time constant and will reach close to its full charge in about five time constants.

Option 3: To quantify the time required for the capacitor to reach its full charge is the correct answer to the given question. The time constant does not determine the supply voltage, calculate the resistance of the capacitor, or measure the capacitance of the capacitor directly. It primarily helps in predicting the charging and discharging rates of the capacitor in an RC circuit.