Final answer:
The question involves calculating a patient's temperature using a digital medical thermometer with a thermistor, by finding the temperature at which the thermistor's resistance is 82% of its value at normal body temperature. It also involves a discussion on the limit to the negative temperature coefficient of resistance as temperatures approach very low values.
Step-by-step explanation:
A digital medical thermometer uses a thermistor to measure temperature by assessing the resistance of the device, which varies with temperature. In question 37 (a), we are asked to calculate a patient's temperature when the resistance of the thermistor is 82.0% of its resistance at the normal body temperature, which is 37.0°C. The thermistor has a temperature coefficient of resistance, denoted by 'a', which is -0.0600/°C. This implies that the resistance decreases as the temperature increases.
To find the unknown temperature, we need to establish the relationship between the resistance of the thermistor at the unknown temperature and its value at 37.0°C. If R0 is the resistance at 37°C, and R is the resistance at the unknown temperature T, we can express that R = 0.82R0. Using the temperature coefficient 'a', we can set up an equation to solve for T.
Part (b) of question 37 asks us to discuss the implication of the negative temperature coefficient at very low temperatures. The hint is that resistance can't become negative, which corresponds to the physical limitation that resistance cannot decrease indefinitely as the temperature drops. This limitation is due to the nature of materials and how they behave at low temperatures.
The context of this problem pertains to thermodynamics and the properties of materials, particularly their electrical properties such as resistance, which is influenced by temperature changes.