Write down the no of significant figures in the following: 0 . 003 m 2 , 0 . 1250 gm cm 2 , 6 . 4 × × 10 6 m , 1 . 6 × 10 - 19 C , 9 . 1 × 10 - 31 kg .

Significant figures are the number of meaningful digit in a measurement. Rule of a significant figure: The non-zero digits in measurement are significant, zeros digit between significant are significant, Trailing zero after decimal place are significant. We can write for given values that 0 . 003 = 3 × 10 - 3 it has 3 significant digits so, the number of the significant figure is one. 0 . 1250 has 1 , 2 , 5 , 0 as significant digits. So, significant figures are four. 6 . 4 × 10 6 has 6 and 4 as significant digits so significant figures are 2. 1 . 6 × 10 - 19 has 1 and 6 as significant digits so significant figures are 2. 9 . 1 × 10 - 31 has 9, 1 as significant digits so significant figures are 2.