Does A star reach its maximum altitude when located on the meridian line?

Answer 1

Yes.

the maximum altitude is called the zenith (directly overhead) (90 degrees from the horizon) (normal to the surface)

if the star you are concerned with is the sun this happens at noon (real noon, not a standard time zone noon)

but it wont happen with the sun unless you are within 23.5 degrees of the equator

if you are in Canada you can have stars in draco, ursa major or cassiopea in the zenith

this happens once every 24 hours if we approximate

or 2 times a year with stars within 23.5 degrees of our latatude if we are more exact

Answer 2

No, a star reaches its maximum altitude when it is at its highest point above the horizon, which typically occurs when the star is on the meridian line. The meridian line is an imaginary line that runs from due North to due South through the observer's zenith.