🔍 Key Concepts

• Insulation resistance vs. temperature (how resistance changes as temperature increases) • Typical rule-of-thumb: resistance of good insulation roughly halves for each 10°C rise in temperature • Understanding what happens to molecular motion and leakage current as temperature increases

💭 Think About

• If the insulation is 10 megohms at 20°C, what generally happens to insulation resistance when the temperature is raised to 40°C? Increase or decrease? • If resistance tends to roughly halve for each 10°C rise, what happens over a 20°C rise? How many times would it be halved? • Compare your estimated resistance at 40°C with each of the multiple‑choice options—what is closest to that value?

✅ Before You Answer

• Be sure you remember that higher temperature usually means lower insulation resistance, not higher • Consider that a 20°C rise may change resistance by a factor of about one-quarter (two halvings) relative to the original value • Verify that the option you choose is significantly lower than 10 megohms, consistent with hotter insulation having more leakage current