List of top Mathematics Questions on Angle between a Line and a Plane asked in WBJEE

Let A be the point (0,4) in the xy-plane and B be the point (2t,0). Let L be AB's midpoint and let AB's perpendicular bisector meet the y-axis M. Let N be the midpoint of LM. The locus of N is

The angle between a normal to the plane 2x-y+2z-1=0 and the X-axis is