$A$ convergent beam of light is incident on a convex mirror so as to converge to a distance $12 \, cm$ from the pole of the mirror. An inverted image of the same size is formed coincident with the virtual object. What is the focal length of the mirror? $(cm)$

In a car,a rear-view mirror having a radius of curvature $1.50 \, m$ forms a virtual image of a bus located $10.0 \, m$ from the mirror. The factor by which the mirror magnifies the size of the bus is close to

The image of an extended object, placed perpendicular to the principal axis of a mirror, will be erect if:
$(a)$ The object is real and the image is real.
$(b)$ The object is virtual and the image is virtual.
$(c)$ The object is real and the image is virtual.
$(d)$ The object is virtual and the image is real.

$A$ concave mirror of focal length $f$ forms an image $n$ times the size of the object. If the image is real, then the distance of the object from the mirror is .......

$A$ mirror of focal length $f$ is immersed in water $(\mu = 4/3)$. The focal length of the mirror in water will be ......

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......$^o$