रिक्त स्थान को भरिए -
1 km = ................ mm = ................ Pm

Explanation

`1km = 1km xx (1000 m)/(1km) xx (100 cm)/(1 cm) xx (10 mm)/(1 cm ) = 10^6 mm`
`1km = 1km xx (1000m)/(1km) xx (1"pm")/(10^(-12) m ) = 10^15 ` pm