#### The decimal expansion of the number $\sqrt{2}$ is.(A) A finite decimal (B) $1.41421$ (C) non-terminating recurring   (D) non-terminating non-recurring

Solution.

Terminating decimals have a finite number of digits after decimal point,
Examples: $1/2 = 0.5, 3/5 = 0.6$
Non terminating decimals are the ones which keep on continuing after decimal point.
Examples: $1/3 = 0.33333...., 5/11 = 0.454545...$
Recurring decimals are those non terminating decimals which have a particular pattern/sequence that keeps on repeating itself after the decimal point. They are also called repeating decimals.
Examples: $1/3 = 0.33333..., 4/11 = 0.363636....$
Non-Recurring decimals are those non terminating decimals which do not have a particular pattern/sequence after the decimal point. They are also called non repeating decimals.
Examples:
$\sqrt{2}=1.414213562373$
$\sqrt{3}=1.732050807568$
$\pi =3.14159265359$
So, the decimal expansion of the number $\sqrt{2}$  is non-terminating non-recurring. It is an irrational number which is a non-terminating non-recurring decimal expansion.
Therefore option (D) is correct.