Light Reflectio...

An object 2 cm high is placed at a distance of 16 cm from a concave mirror, which produces a real image 3 cm high. What is the focal length of the mirror ?

A rod of length $$10 \ cm$$ lies along the principal axis of a concave mirror of focal length $$10 \ cm$$ in such a way that its end closer to the pole is $$20 \ cm$$ away from the mirror. The length of the image is

A convergent beam of light passes through a diverging lens of focal length $$0\cdot2\ m$$ and comes to focus $$0\cdot3\ m$$ behind the lens. The position of the point at which the beam would converge in the absence of the lens is 

An object is placed at $$20\ cm$$ form a convex mirror of focal length $$10\ cm.$$ The image formed by a mirror is 

A square wire of side 1 cm is placed perpendicular to the principle axis of a concave mirror of focal length 15 cm at a distance of 20 cm. The area enclosed by the image of the wire is:

An object is placed at a distance of $$5$$ cm from a convex lens of focal length $$10$$ cm, then the image 

An object is placed at a distance of $$25cm$$ on the axis of a concave mirror, having focal length $$20cm$$. Find the lateral magnification of an image

An object is at $$0.06$$ m from a convex lens of focal length $$0.10$$m. Find the position of the image.

A candle placed $$25 \,cm$$ form a lens forms an image on a screen placed $$75 \,cm$$ on the other side of the lens. The focal length and type of the lens should be

Time taken by the sunlight to pass through a window of thickness 4mm whose refractive index is 1.5 is