If $x-2=t^2$ and $y=2t$ are the parametric equations of the parabola $y^2=a(x-b)$,then the value of $a+b$ equals

If two perpendicular rays from the focus of the parabolic surface $y^2 = 4x$ are incident at points $A(t_1^2, 2t_1)$ and $B(t_2^2, 2t_2)$ such that $t_1t_2 = -1$,then the distance between the reflected rays is -

The points on the parabola $y^2 = 12x$ whose focal distance is $4$ are

$A$ set of parallel chords of the parabola $y^2 = 4ax$ have their mid-points on:

Two parabolas have the same focus $(4, 3)$ and their directrices are the $x$-axis and the $y$-axis,respectively. If these parabolas intersect at the points $A$ and $B$,then $(AB)^2$ is equal to

Find the equation of the normal to the parabola $y^2 = 16x$ having a slope of $-1/4$.