Ncert Exercises & Solutions

1.27 Convert the following into basic units:

(i) 28.7 pm

(ii) 15.15 pm

(iii) 25365 mg

(i) 28.7 pm :

1 pm = 10^{- 12} m

∴ 28.7 pm = 28.7 \times 10^{- 12} m

= 2.87 \times 10^{- 11} m

(ii) 15.15 pm :

1 pm = 10^{- 12} m

∴ 15.15 pm = 15.15 \times 10^{- 12} m

= 1.515 \times 10^{- 12} m

(iii) 25365 mg :

1 mg = 10^{- 3} g

25365 mg = 2.5365 \times 104 \times 10^{- 3} g Since,

1 g = 10^{- 3} kg

2.5365 \times 101 g = 2.5365 \times 10^{- 1} \times 10^{- 3} kg

∴ 25365 mg = 2.5365 \times 10^{- 2} kg