Question

1 metre can be defined as distance travelled by light in $\frac{1}{299792458}$ seconds in vacuum.

• A. True
• B. False

Answer 1

The correct option is A True

A suitable standard of unit is one which does not change with time or place. For example, if we take a rod as a standard, then it might contract during winters or expand in summers. In case of a foot, it varies from person to person, so it is not a suitable option. But, the speed of light in vaccum is constant throughout the universe; hence it is a suitable standard.