Answer :
Final answer:
Without specific information regarding the baseline resistance at 20.0 °C and temperature coefficient for the platinum RTD, the actual resistance cannot be accurately determined from the given options.
Explanation:
The actual resistance of the platinum RTD can be determined if we know the resistance of the RTD at 20.0 °C and how it changes with temperature. Unfortunately, the provided information does not specify a baseline resistance at 20.0 °C, nor does it provide a specific temperature coefficient that we would use to calculate the change in resistance at a different temperature. RTDs typically change resistance with temperature in a predictable way, but without the aforementioned information for this particular RTD, we cannot accurately answer the question regarding its resistance.
For a standard platinum RTD (PT100), which has a resistance of 100 Ω at 0°C, the resistance increases with temperature due to the positive temperature coefficient of platinum. Assuming this standard, if the resistance increase is 40.0% greater at 100.0 °C than at 20.0 °C, you would calculate the resistance at 100.0 °C by multiplying the RTD’s base resistance by 1.40 (since 40% greater means 1 + 0.40). Using a base resistance of 100 Ω (which is a common standard for platinum RTDs), the actual resistance at 100.0 °C would therefore be 100 Ω * 1.40 = 140 Ω. However, since 140 Ω is not an option given in your question, we cannot select it. If the baseline resistance or the nature of the RTD is different from the standard PT100, the actual resistance would need to be determined accordingly.
