Subjective
G. Answer the following questions:
1. What is meant by measurement?
2. What do you understand by the term unit?
3. State two characteristics of a standard unit.
4. Define length. What is its SI unit?
5. Name two devices used for measuring length.
6. What is mass?
7. Name two multiples and two submultiples of the unit of mass.
8. Define standard metre.
9. What is time? What is its SI unit?
10. Name two devices used to measure time.
11. What do you mean by temperature? State the SI unit of temperature.
Answers
Answer:
1. the act or process of measuring something
2. Unit is the quantity of a constant magnitude which is used to measure the magnitudes of other quantities of the same nature.
3. (i) It should be easily understandable. (ii) It should be changed with change in physical factors.
4.
5. a ruler, a Vernier caliper, and a micrometer screw gauge. Vernier caliper
6. Mass is a measure of the amount of matter in an object. Mass is usually measured in grams (g) or kilograms (kg).
7. Submultiples of kilogram are decagram ,centigram etc. And multiples of kilogram is megagram(1 tonne) , gigagram
8. The Standard meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.
9. Time is a quantity , which is the ratio of distance and speed and its S.I.unit is second
10.Clocks and Watches
11.The kelvin (K) is the base unit for temperature. ... The kelvin measurement intervals are equal to those of the Celsius degree scale.