Ch-2 Physical quantities and measurements

Science Subjective Questions

Measurement and Temperature: Subjective Questions with Answers

Practice important subjective questions on laboratory thermometer, clinical thermometer, stopwatch, units, multiples, and submultiples with click-to-reveal answers.

Subjective Questions

Click on “Show Answer” to reveal the answer for each question. These questions are useful for revision, oral practice, and written exam preparation.

1. Differentiate between laboratory thermometer and clinical thermometer.

A laboratory thermometer is used to measure a wide range of temperatures in laboratories, usually from -10°C to 110°C, and does not have a kink. A clinical thermometer is used to measure body temperature, usually ranges from 35°C to 42°C, and has a kink to prevent mercury from falling back.

2. How is digital clock different from stopwatch? What are the uses of stopwatch?

A digital clock displays the current time continuously, while a stopwatch is used to measure time intervals. A stopwatch is used in laboratories, sports events, and experiments to measure short time intervals accurately.

3. What is the use of kink in clinical thermometer?

The kink in a clinical thermometer prevents the mercury from flowing back into the bulb, allowing the temperature reading to remain fixed even after removing it from the patient's body.

4. List down the conventions that we follow while writing units. Give an example wherever necessary.

Unit symbols should not be followed by a full stop. A space is left between the number and the unit symbol, such as 5 m. Symbols are usually written in lowercase, except for units named after a person, such as N for Newton. Plural is not used with unit symbols. For example, we write 10 kg, not 10 kgs.

5. Distinguish between multiples and submultiples of units.

Multiples of units are larger units formed by multiplying the base unit. For example, kilometre = 1000 metres. Submultiples are smaller units formed by dividing the base unit. For example, centimetre = 1/100 of a metre.

Revision Tip: Learn the difference between instruments, their ranges, and their uses. Also remember the correct way to write SI units.

Frequently Asked Questions

What is the main difference between a laboratory thermometer and a clinical thermometer?

A laboratory thermometer measures a wide range of temperatures, while a clinical thermometer measures human body temperature.

Why does a clinical thermometer have a kink?

A clinical thermometer has a kink to stop mercury from falling back quickly, so the temperature reading can be noted after removing it from the body.

What is the use of a stopwatch?

A stopwatch is used to measure short time intervals accurately in experiments, sports, and other activities.

How should unit symbols be written correctly?

Unit symbols should be written without a full stop, with a space after the number, and without plural form. For example, write 10 kg, not 10 kgs.

What are multiples and submultiples of units?

Multiples are larger units made by multiplying a base unit, while submultiples are smaller units made by dividing a base unit.

DESIGNED BY SHALEEN SHEKHAR AND CONCEPT BY TEACHER RITU