$A$ concave mirror of focal length $60 \ cm$ forms a real image of size $5$ times the size of a real object. Find the distance between the mirror and the object. (in $cm$)

The circular boundary of the concave mirror subtends a cone of half-angle $\theta$ at its centre of curvature. The minimum value of $\theta$ for which a ray incident on this mirror parallel to the principal axis suffers more than one reflection is......$^o$

In a concave mirror experiment,an object is placed at a distance ${x_1}$ from the focus and the image is formed at a distance ${x_2}$ from the focus. The focal length of the mirror would be

$STATEMENT-1$: The formula connecting $u, v$ and $f$ for a spherical mirror is valid only for mirrors whose sizes are very small compared to their radii of curvature. because
$STATEMENT-2$: Laws of reflection are strictly valid for plane surfaces, but not for large spherical surfaces.

$A$ ray of light is incident on a convex mirror along a vector $3\hat i + 4\hat j + 12\hat k$. The normal to the convex mirror at the point of incidence is along $3\hat i + 4\hat j$. The unit vector along the reflected ray is:

$A$ thin rod of length $f/3$ lies along the axis of a concave mirror of focal length $f$. One end of its magnified image touches an end of the rod. The length of the image is