The focal length of a concave mirror is $50 \, cm$. Where should an object be placed so that its image is two times magnified and inverted?

Explain the ray diagram for the image obtained by a concave mirror by considering three rays.

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

$A$ 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:

When an object is placed at a distance of $25 \; cm$ from a mirror,the magnification is $m_1$. The object is moved $15 \; cm$ away with respect to the earlier position,magnification becomes $m_2$. If $\frac{m_1}{m_2} = 4$,the focal length of the mirror is: (in $; cm$)

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.