🔍 Key Concepts

• Formula for the time constant (tau) in an RC circuit • How to correctly convert microfarads to farads and kilohms to ohms • How multiplying very large/small numbers affects the order of magnitude of the answer

💭 Think About

• What is the basic formula that relates resistance, capacitance, and time constant in an RC circuit? Write it down before doing any calculations. • Convert the given resistor and capacitor values fully into base SI units (ohms and farads). What powers of ten are involved? • After multiplying R and C, what is the approximate size (order of magnitude) of the result: much less than 1 second, about 1 second, tens of seconds, hundreds, or thousands of seconds?

✅ Before You Answer

• Make sure you have converted 100 microfarads correctly into farads before multiplying. • Make sure you have converted 470 kilohms correctly into ohms before multiplying. • After you calculate the numerical value, compare it to each choice and check if the order of magnitude (10^x) really makes sense.