🔍 Key Concepts

• RC circuit charging curve and what the voltage vs. time graph looks like • Definition of a time constant (τ) in an RC circuit • The special percentage (63.2%) and how it relates to the time constant

💭 Think About

• When a capacitor charges through a resistor, does the voltage rise instantly to the supply value, or follow a particular mathematical curve? • What specific name is used in electronics for the time it takes for this curve to reach about 63% of its final value? • Among the options, which one is an actual, standard term used in basic RC circuit theory, rather than a made‑up phrase?

✅ Before You Answer

• Identify which option mentions time constant directly and recall how it’s symbolized (usually τ). • Eliminate answers that talk about a rate, period, or factor if they don’t match any standard electronics terminology you’ve seen. • Confirm which term is explicitly defined as the time to reach 63.2% of the final (steady‑state) value in RC charging.