Chapter 2 – History and the Concept of ‘Time’
EXERCISES
1. Fill in the blanks.
(a) The calendar we use today is based on the _______.
Ans: Christian era or Common era.
(b) The period before the Common Era is known as the time _______.
Ans: Before the common Era (BCE) or Before Christ (BC).
2. Answer each question in one sentence.
(a) Which scientific methods are used to estimate the age of the layers of soil and the remains found in them?
Ans: The dating techniques, such as the carbon-14 analysis and the Tree-ring analysis, are used to estimate the age of the layers of soil and the remains found in them.
(b) How is the first century of the Common Era written?
Ans: The first century of the Common Era is written as 1–100 AD.
3. Answer the following questions in brief.
(a) What is meant by the unilinear division of time?
Ans:
(i) Seven days make a week, two weeks make a fortnight, and four weeks make a month.
(ii) Twelve months make a year, and 100 years make a century.
(iii) Ten centuries, or 1000 years, make a millennium.
(iv) Such a method of dividing time is called unilinear division of time.
(b) What are the units of measuring time?
Ans:
(i) The units of measuring time are the second, minute, hour, day, week, fortnight, month, year, century, and millennium.
(ii) A second is the smallest unit of time. There are various methods of measuring time in different parts of the world.
(iii) Of these, the Common Era or Christian Era is the most widely used.
4. Complete the chart given below.
Ans:
