Quiz : How Much You Know About Temperature?

To calibrate a thermometer, both a lower fixed point and an upper fixed point are required. This is because a lower fixed point, such as the freezing point of water, provides a reference for the lowest temperature that the thermometer can accurately measure. Similarly, an upper fixed point, such as the boiling point of water, provides a reference for the highest temperature that the thermometer can accurately measure. By calibrating the thermometer using these two fixed points, the accuracy and reliability of temperature measurements can be ensured across the entire temperature range.

If the liquid used in a liquid-in-glass thermometer does not expand uniformly with temperature, it means that the volume of the liquid does not increase or decrease at a constant rate as the temperature changes. This will result in a non-linear relationship between the temperature and the volume of the liquid. As a result, the scale of the thermometer will not be evenly spaced and the markings will not be equally spaced apart. Instead, the markings will be closer together in some regions and farther apart in others, leading to a non-linear scale.

A thermocouple is the best thermometer for measuring rapidly-changing temperatures because it is highly responsive and can quickly detect and measure temperature changes. Unlike other types of thermometers, such as a liquid-in-glass thermometer or a clinical thermometer, a thermocouple uses two different metals to generate a voltage that is proportional to the temperature difference between the two junctions. This allows for fast and accurate measurements of rapidly-changing temperatures.

The sensitivity of a clinical thermometer is affected by the diameter of the bore. A smaller diameter bore allows for a greater expansion of the liquid inside the thermometer when there is a change in temperature, resulting in a more sensitive reading. A larger diameter bore would have less expansion of the liquid for the same change in temperature, making it less sensitive. Therefore, the diameter of the bore is a crucial factor in determining the sensitivity of the clinical thermometer.

A liquid-in-glass thermometer is sensitive to a small change of temperature because of its very narrow bore. The narrow bore restricts the flow of the liquid, causing it to expand or contract more easily in response to temperature changes. This allows for a more precise measurement of temperature as even a small change in temperature will result in a noticeable change in the liquid level within the narrow bore.

A clinical thermometer needs to be able to measure small changes in body temperature accurately. The bore of the capillary tube being narrow allows for more precise measurements because it restricts the movement of the mercury inside the tube. This means that even a small change in body temperature will result in a noticeable change in the position of the mercury in the tube, allowing for accurate readings.

The physical property of mercury that varies with temperature and enables the thermometer to operate is volume. As the temperature increases, the volume of the mercury expands, causing it to rise in the glass tube of the thermometer. Conversely, as the temperature decreases, the volume of the mercury contracts, causing it to lower in the tube. This change in volume is used to measure and indicate the temperature.

Thermometer C has the greatest sensitivity because it has the steepest slope on the graph, indicating that it has a greater change in temperature for a given change in reading. Thermometer D has the greatest range because it covers a wider range of temperatures on the graph compared to the other thermometers.

The correct answer is B. In order to calibrate the thermometer at the steam point, the values of t1 and t2 should be 0°C and 100°C respectively. This is because the steam point is defined as the temperature at which water boils, which is 100°C at standard atmospheric pressure. Therefore, t1 should be 0°C (the freezing point of water) and t2 should be 100°C (the boiling point of water).

The mass of the mercury remains constant because mass is a measure of the amount of matter in an object, and it does not change with temperature. As the temperature increases, the mercury expands, causing an increase in volume. However, the density of the mercury, which is the mass per unit volume, remains constant because the mass does not change. The internal energy of the mercury increases with temperature as the kinetic energy of the particles increases. Therefore, the only option that remains constant is the mass of the mercury.

When the liquid in the thermometer is replaced by a different liquid that expands more for the same temperature rise, the new thermometer will have greater sensitivity because the liquid will expand more and show a larger change in volume for a given change in temperature. However, the range of the thermometer will be smaller because the liquid will reach its maximum expansion more quickly, limiting the range of temperatures that can be accurately measured. Therefore, the correct answer is greater sensitivity but a smaller range.

Decreasing the volume of liquid and increasing the diameter of the bore of the thermometer will produce the greatest increase in sensitivity. This is because a smaller volume of liquid will be more responsive to temperature changes, and a larger diameter of the bore will allow for better heat transfer between the liquid and the thermometer, increasing the sensitivity of the thermometer.