Chapter 1 Temperature and Thermometers
1. Temperature is a physical quantity that measures the degree of hotness or coldness of an object. The most common scales are the Celsius scale and Kelvin scale. Their respective units are °C and K.
3. B. The lowest possible temperature is −273°C.
3. (a) Incorrect. A physical quantity is a thermometric property as long as it changes with temperature. Whether it changes linearly with temperature is not a necessary condition of being a thermometric property.
(b) Incorrect. A physical quantity is a thermometric property as long as it changes with temperature. Whether it increases or ...view middle of the document...
The increase in length of the mercury column when the temperature rises from 0°C to 37°C is l2 = l − 5.
The length of the mercury column is 12.4 cm if the thermometer is used to measure the normal human body temperature.
An object expands when the temperature of the object increases because the average distance between the molecules of that object increases.
2. Statement 1 is incorrect.
Even at the lowest possible temperature of 0 K, the total kinetic energy of the molecules of an object will not drop to zero.
Statement 2 is incorrect.
The object may have different average molecular kinetic energy. The temperature of two objects is the same only if they have the same average kinetic energy due to the random motion of the molecules in the objects.
1. (a) thermocouple thermometer
(b) rotary thermometer
(c) resistance thermometer
(d) infrared thermometer
3. One of the thermometers has a narrower capillary tube.
4. Let θ be the temperature when the length of the liquid column is l.
(a) When the length of the liquid column is 4.5 cm,
When the length of the liquid column is 4.5 cm, the temperature is −5°C.
(b) When the length of the liquid column is 7.5 cm,
When the length of the liquid column is 7.5 cm, the temperature is 25°C.
(c) When the length of the liquid column is 16 cm,
When the length of the liquid column is 16 cm, the temperature is 110°C.
5. (a) Let l be the length of the liquid column in the thermometer when the thermometer is placed in a liquid of 51°C. From Q4, by proportion,
The length of the liquid column is 10.1 cm when the liquid is kept at 51°C.
(b) The diameter of the capillary tube may not be uniform, so the length of liquid column does not change linearly with temperature.
6. (a) correct
Chapter Exercise (p.27)
7. (a) 200°C, mercury-in-glass thermometer (1A)
(b) −200°C, thermocouple thermometer (1A)
(c) 200°C, rotary thermometer (1A)
(d) −20°C, alcohol-in-glass thermometer/thermistor thermometer/rotary thermometer (1A)
(e) 20°C, mercury-in-glass thermometer/alcohol-in-glass thermometer (1A)
(f) 2000°C, thermocouple thermometer (1A)
8. (a) Mercury (1A) should be used in the thermometer. The working range of a mercury-in-glass thermometer is between −30°C and 400°C while that of the alcohol-in-glass thermometer is between −100°C and 110°C. Only the mercury one is suitable (1A).
(b) rotary thermometer (Any reasonable answers) (1A)
(c) freezer (Any reasonable answers) (1A)
9. (a) The capillary tube is made very narrow to improve the sensitivity of the thermometer. (1A)
(b) The glass wall of the bulb is very thin to facilitate heat...