Q.No.4) State the rules for determining significant figure
Answers
Answer:
Rules for determining significant figures :
(i) Retain only one uncertain digit in the measurement of a physical quantity.
(ii) When the value of the measurement is to be rounded off to given number of
significant figures, then the figures to be dropped is
(1) less than 5, then the last
significant figure is left unchanged
(2) 5 or greater than 5, the last significant
figure is increased by one.
(iii) The zeros on the right hand side of the number are significant because they
indicate the accuracy of the instrument used for measurement.
(iv) The zeros on the left hand side of the number are not significant, e.g., the
number 0.0753 has only three significant figures.
(v) If the number of digits is more than the number of significant figures, the number
should be expressed in the power of 10. e.g., the mass of the earth is written as
5.98 1024kg, as it is known only upto 3 significant figures.