Question

A metre ruler is graduated in:
(A) $m$
(B) $cm$
(C) $mm$
(D) $km$

Answer 1

A metre ruler is a device by which if we want to measure the actual size of any small object in inches or centimetres, then the metre ruler is needed. It is the most convenient way to measure something on a small scale.

Complete answer:
A metre ruler graduated in $mm$ .
A metre ruler is a gadget or a sort of ruler that is used to measure the length and distance of various objects. A metre rule has a length of one metre, which is equal to one hundred centimetres, as the name suggests.
A metre ruler has a length of one metre, which is equal to one hundred centimetres, as the name suggests. A metre rule, on the other hand, is divided into smaller units called millimetres, with each centimetre divided into ten millimetres.
In a simple word, we can say about the meter ruler: A metre rule is a gadget or a sort of ruler that is used to measure the length and distance of various objects. A metre rule has a length of one metre, which is equal to one hundred centimetres, as the name suggests. A metre rule, on the other hand, is divided into smaller units called millimetres, with each centimetre divided into ten millimetres. As a result, up to one millimetre, a metre rule can be used to measure the shortest length. A metre rule can be used for more than just measuring distances; it can also be used to draw straight lines and cut blades.
The science of measuring the lengths and widths of objects is practised all across the world, and different nations and regions use different names to describe these measures. In the United States of America, for example, customary units are used to measure lengths. Miles, yards, inches, and feet are the most common units. Other nations, on the other hand, utilise metric measurements, which are used in practically every country on the planet. Kilometers, metres, centimetres, centimetres, and other units are used in metric measurements. Despite the differences in terminology, the underlying principles of measuring are the same for both customary and metric units of measurement.
Hence, the correct option is (C) $mm$

Note:
As we know, there are two precision metre rulers: One is accuracy, and one is resolution. Any measuring device can be inaccurate in some ways. The resolution of a metre stick is marked simply at zero and one metre is one metre, although the stick may be absolutely precise. The resolution is to the decimetre if a stick has markings at tenths of a metre, for example.