If the half-life of a reaction is halved when the initial concentration of the reactant is doubled,what is the order of the reaction?

If the line $2x + 5y = 12$ intersects the ellipse $4x^2 + 5y^2 = 20$ in two distinct points $A$ and $B$,then the mid-point of $AB$ is

If $(2, -1, 3)$ is the foot of the perpendicular drawn from the origin to a plane,then the equation of that plane is

$A$ convex lens is made up of three different materials as shown in the figure. For a point object placed on its axis,the number of images formed is:

What are the products obtained when ammonia is reacted with excess chlorine?

If the axes are rotated through an angle $45^{\circ}$ in the positive direction without changing the origin,then the coordinates of the point $(\sqrt{2}, 4)$ in the old system are