Question

Arrange the following lengths in their increasing magnitude:
1meter,1centimeter,1kilometer,1millimeter
(A) $ 1metre < 1centimetre < 1kilometre < 1millimetre $
(B) $ 1millimetre < 1metre < 1centimetre < 1kilometre $
(C) $ 1millimetre < 1centimetre < 1metre < 1kilometre $
(D) None of these.

Answer 1

Hint
Conversion of units is done to measure the quantities and to know how kilometre, meter, centimetre and millimetre are linked with each other.
Converting the kilometre to meter, meter to centimetre, centimetre to millimetre, to we will see which unit is big and which is small. Then we will find the increasing order of the units and find the correct option.

Complete step by step answer
We know that the conversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.
So different units’ conversion is:
1kilomeetr=1000meter
1meter =100centimeetr and
1centimeetr=1millimeter
Increasing order means to arrange the number from lowest to highest, so according to above conversion the lowest quantity is millimetre as it is smaller than centimetre, meter and kilometre.
The highest unit is kilometre as it is greater than millimetre, centimetre and metre.
Also, we can see that meter is greater than centimetre.
So, the arrangement can be $ 1mil\lim etre < 1centimetre < 1metre < 1kilometre $ .
So, the correct option is (C).

Note
These conversions are used when we have calculated the quantity other than the quantity given in question. For example, if we have given quantity in kilometers and we have to convert the length in meters then we will use these conversions.