Regarding Private constructor & static constructor in c#

Question

Respected Sir/Madam,

                               Please give me correct answer with  examples.

                               1-Why we use Private constructor in c#.
                               2-Why we use static constructor in c#.
                               3-When i'll use Private constructor in c#.
                               4-When i'll use static constructor in c#.


Thanks & Regards:

Sachin Sachan

Mob:[phone]

Email: [email protected]