In which scenario would you typically use a capacitor?

Using a capacitor to block AC signals is a fundamental application of capacitors in electronic circuits. Capacitors can allow AC signals to pass through while preventing DC signals from flowing. This characteristic is particularly useful in coupling and decoupling applications, where it's essential to separate different parts of a circuit without allowing direct DC connections.

For instance, in audio applications, capacitors are often used to couple audio signals between stages of an amplifier while blocking any DC component that might disrupt the operation or sound quality. The alternating nature of AC signals allows the capacitor to charge and discharge, thus enabling the AC to pass while blocking any steady DC voltage present.

Other options such as storing digital data or rectifying AC signals are functions related more to other components - like memory chips for data storage or diodes for rectification, respectively. Providing a constant current supply typically involves regulated power supply circuitry rather than the inherent properties of capacitors. Therefore, the use of a capacitor specifically to block AC signals is both a fundamental and common application, highlighting its role in managing signal integrity in various electronic systems.