🔍 Key Concepts

• RC time constant (τ = R × C) and how it controls the exponential charge and discharge curves shown in the graph • Uses of an RC network where the exact rise and fall times of voltage are important • Difference between circuits that mainly handle steady DC levels versus those that handle waveforms, pulses, or delays

💭 Think About

• In which of the listed applications would the exact shape and timing of the capacitor’s charge and discharge curve be critical to the circuit’s purpose? • Looking at the graph, the voltage changes predictably over multiples of τ. Which option most clearly depends on creating a controlled delay or controlled edge shape of a signal? • For each choice, ask whether the function is mainly about timing of signals or about providing/controlling power levels. Which group naturally needs RC timing curves?

✅ Before You Answer

• Identify which choice most clearly involves delays, wave-shaping, or control of pulse width/edges. • Eliminate any choices that mainly involve power conversion or protection, where the exact exponential time curve of a small RC is not the primary function. • Confirm that your final choice describes a circuit where changing τ (R or C) directly changes how long it takes a voltage to reach a certain percentage level, just like the plotted curves in the illustration.