Spherical Aberrations

Q. A real image of a distant object is formed by a planoconvex lens on its principal axis. Spherical aberration is

1. absent
2. smaller if the curved surface of the lens faces the object
3. smaller if the plane surface of the lens faces the object
4. the same whichever side of the lens faces the object

Q. For the diagram shown below, identify the correct statement regarding object (AB), lens and image (A'B'). Assume that the size of object and image is same.

1. Point $B$, its image $B^{\prime }$ and optical centre $\left(O\right)$ of the lens are collinear.
2. None of the above
3. Point $B$, its image $B^{\prime }$ and optical centre $\left(O\right)$ of the lens are non- collinear.
4. $B^{\prime }$ is the point on the virtual image of the object.