Caricature quiz on Light

A short straight object of height 100cm lies before the central axis of a spherical mirrors of mod of focal length is 40cm. The image of object produced by the mirror is of height 25cm and has the same orientation of the object. One may conclude from the information

• image is virtual, opposite side of convex mirror

• image is virtual, opposite side of concave mirror

• image is real, same side of convex mirror

• image is real, same side of concave mirror+

A concave mirror for face viewing has focal length of 0.4m. The distance at which you hold the mirror from your face in order to see your image upright with a magnification of 5 is

• 0.24m

• 1.60m

• 0.32m

• 0.16m

Image of an object approaching a convex mirror of radius of curvature 20m along its optical axis is observed to move from 25/3m to 50/7m in 30 seconds. The speed of the object in m/sec is

A thin rod of length f/3 is placed along the optic axis of a concave mirror of focal length f such that its image which is real and elongated, just touches the rod. The magnification is

A point object is placed at the centre of a glass sphere of radius 6cm and refractive index 1.5. The distance of the virtual image from the surface is

• 6cm

• 4cm

• 12cm

• 9cm