Question

Which of these will be in centimetres and which of these will be in meters?
(A) Width of the computer screen
(B) Length of pagdi worn by Sikhs
(C) Height of a one year old child

Answer 1

Hint: The problem is related to the use of units of measurement. Units of measurement are the definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. In other words, a unit of measurement of a certain kind of thing can be used to express other quantities of that particular kind as a multiple of the unit. In the problem, we have to decide on the suitable units for measuring lengths of the objects given to us in the options.

Complete step by step solution:
The metres and centimetres are the units to measure the length of physical commodities or items. A metre is abbreviated as m and centimetre is abbreviated as cm. A metre is the SI unit for measuring lengths of objects. A centimetre, on the other hand, is a smaller unit for measuring lengths of items.
Hence, a centimetre is used to measure smaller lengths of objects in comparison to a metre.
So, now we look upon the options and comment on the most suitable unit of measurement for that object.
The width of a computer screen is smaller than a metre. Also, a computer screen is about the length of a half a metre. Hence, the computer screen is generally measured in centimetres.
Now, the pagdi worn by Sikhs is a quite long piece of cloth. The length of the pagdi usually varies from $3.5$ metres to $6$ metres. Hence, the pagdi worn by Sikhs is generally measured in metres.
Also, we know that a one year old child is very short in height. So, the smaller units of length can be used to measure the height of a child that is one year old. Hence, centimetres is the unit for the height of a one year old child.

Note: Every physical quantity has multiple units for measurement. We have different units for solid quantity, liquid quantity and gaseous quantity. Every quantity has a measurement unit from the low quantity to the high quantity. All the units used for measuring a particular physical quantity can be changed into one another by multiplying or dividing by a suitable factor.