Chapter 7: Temperature and its Measurement
Comprehensive Exercise (Made for exam preparation)
Class 6 Science
Question 1: Choose the correct option (Multiple Choice Questions):
1. What is the reliable measure of the hotness or coldness of a body?
Answer: (B) Temperature.
2. Which device is used to measure human body temperature?
Answer: (C) Clinical thermometer.
3. How should a laboratory thermometer be held while measuring temperature?
Answer: (D) Vertically.
4. What is the lowest temperature that can be achieved, according to scientific understanding?
Answer: (C) Absolute zero (-273.15 °C).
5. While measuring the temperature of boiling water, what happens to its temperature?
Answer: (C) It remains constant.
Question 2: Fill in the blanks with the appropriate words:
- 1. We cannot always rely upon our sense of touch to decide correctly whether a body is hot or cold.
- 2. A device that measures temperature is called a thermometer.
- 3. Digital clinical thermometers show temperatures digitally and run on batteries.
- 4. When measuring the temperature of a liquid, the bulb of a laboratory thermometer should not touch the bottom or the sides of the beaker.
- 5. The temperature at the core of the Sun reaches as high as 15 million degrees Celsius.
Question 3: State whether the following statements are True or False:
- 1. A hotter body has a higher temperature than a colder body.
Answer: True. - 2. A clinical thermometer can be used to measure the temperature of boiling water.
Answer: False (Clinical thermometers are meant for human body temperature). - 3. The temperature must be read while the laboratory thermometer is immersed in water.
Answer: True. - 4. The temperature of ice keeps changing constantly while it is melting.
Answer: False (It remains constant while melting). - 5. Room thermometers are used to give an approximate idea of the air temperature in a room.
Answer: True.
Question 4: Match the items in Column 'A' with the correct items in Column 'B':
| Column 'A' | Column 'B' |
|---|---|
| 1. Clinical thermometer | (a) Gives an idea of air temperature |
| 2. Laboratory thermometer | (b) -273.15 °C (0 kelvin) |
| 3. Room thermometer | (c) Measures human body temperature |
| 4. Absolute zero | (d) Reliable measure of hotness of a body |
| 5. Temperature | (e) Used for experimental purposes like measuring warm water |
Correct Matches:
- 1 → (c) Measures human body temperature
- 2 → (e) Used for experimental purposes like measuring warm water
- 3 → (a) Gives an idea of air temperature
- 4 → (b) -273.15 °C (0 kelvin)
- 5 → (d) Reliable measure of hotness of a body
Question 5: Classification. Classify the following situations based on which thermometer is appropriate to use:
Situations: 1. A nurse checking a patient's fever, 2. Measuring the temperature of melting ice, 3. Checking the maximum air temperature of the day, 4. Finding the temperature of boiling water in an experiment, 5. A mother checking if her child has a fever.
- Clinical Thermometer: 1. A nurse checking a patient's fever, 5. A mother checking if her child has a fever.
- Laboratory Thermometer: 2. Measuring the temperature of melting ice, 4. Finding the temperature of boiling water in an experiment.
- Room Thermometer: 3. Checking the maximum air temperature of the day.
Question 6: Answer the following questions in one sentence:
1. What does the difference in temperature between two bodies tell us?
Answer: The difference in temperature between two bodies tells us how hot a body is in comparison to another body.
2. Why do we need a thermometer?
Answer: We need a thermometer because our sense of touch is not always reliable to accurately measure how hot or cold a body is.
3. What is the correct eye position while reading a laboratory thermometer?
Answer: While reading the thermometer, the eye should be directly in line with the level of the liquid column.
4. What is a digital clinical thermometer?
Answer: It is a thermometer used to measure human body temperature that runs on batteries and displays the temperature digitally.
5. What is 'Absolute zero'?
Answer: Absolute zero is the lowest temperature that can be achieved, which is close to -273.15 °C (0 kelvin).
Question 7: Give scientific reasons:
1. Reason: We cannot always rely on our sense of touch to determine hotness or coldness.
Answer: Because our senses can be easily confused; for example, if you put one hand in hot water and another in cold water, and then both in normal water, one hand will feel the water is cool while the other will feel it is warm.
2. Reason: The bulb of a laboratory thermometer should not touch the bottom or sides of the beaker while measuring the temperature of a liquid.
Answer: Because touching the bottom or sides would measure the temperature of the container rather than the accurate temperature of the liquid inside it.
3. Reason: We must hold the laboratory thermometer vertically, not tilted.
Answer: Holding it vertically ensures accurate contact with the liquid and helps in reading the correct level of the liquid column inside the thermometer.
4. Reason: You must read the laboratory thermometer while it is immersed in water.
Answer: Because as soon as you take it out of the water, the temperature reading might start changing according to the surrounding air.
5. Reason: We use clinical thermometers only for the human body and not for boiling water.
Answer: Because clinical thermometers have a specific short range suitable only for human body temperatures, and placing them in boiling water can break them due to high heat.
Question 8: Answer the following questions in short (2-3 sentences):
1. State any two important rules for the correct way of measuring temperature using a laboratory thermometer.
Answer: Two important rules are: (1) The thermometer should be held vertically and not tilted. (2) Its bulb should be completely immersed in the liquid but should not touch the bottom or the sides of the container.
2. How do you find the smallest value (least count) that a thermometer can read?
Answer: We first find the temperature difference between two bigger marks (e.g., 10 °C). Then we count the number of small divisions between them (e.g., 10 divisions). The smallest value is the difference divided by the number of divisions (e.g., 10/10 = 1 °C).
3. What happens to the temperature of water when it starts boiling?
Answer: When water starts boiling, its temperature stops rising and becomes constant. It remains constant as long as the water continues to boil.
4. Differentiate between a clinical thermometer and a laboratory thermometer based on their usage.
Answer: A clinical thermometer is specifically designed to measure human body temperature only. On the other hand, a laboratory thermometer is used for other experimental purposes, like measuring the temperature of boiling water or melting ice.
5. What is a room thermometer used for? Where can you usually find it?
Answer: A room thermometer is used to measure the air temperature and gives an approximate idea of the room temperature. It is usually hung on the walls of school laboratories, doctors' clinics, and hospitals.