An abject is placed at a distance of 30 cm from a lens. The image is formed at a distance of 45 cm on the other side.of the lens. Identify the nature of the lens and also find its focal length.

When an object is placed at a distance 6 cm from a concave lens a virtual image is formed at a distance 4cm from it. Find the focal length of the lens.

A needle placed at 30 cm from the lens forms an image on a screen placed 60 cm on the other side of the lens. Identify the type of lens and determine the focal length.

An object is placed at a distance of 15 cm from a spherical mirror and a real image is formed at a distance of 30 cm in front of the mirror. Find the focal length of the mirror. Also, identify the mirror.

An object is placed at the focus of concave lens. Where will its image be formed?

An object is placed at the focus of Convex lens. Where will the image be formed?

An object is placed at a distance of 50 cm from a concave lens of focal length 20 cm. Find the nature and position of the image.

An object is placed at a distance of 30 cm from a convex lens. A real image of magnification 1.5 is formed. Find the location of the image and the focal length of the tens.

An object is placed at a distance of 10cm from a convex mirror of focal length 15cm. Find the position and nature of the image.