Find the position of an object,which when placed in front of a concave mirror of focal length 20 cm,produces a virtual image,which is twice the size of the object.

A concave mirror has a focal length of 20 cm and an object is placed at a distance of 16 cm from it.Find the position of the image formed by it.

A concave mirror of focal length 15 cm forms an image having twice the linear dimenstions of the objet.The position of the object,when the image is virtual,will be

A concave lens is placed in contact with a convvex lens of focal lenght 25 cm.the combinatin produces a real image at a distance of 80 cm,when the object is at a distance of 40 cm.What is the focal length of the concave lens?

A concave mirror has a focal length of 10 cm and an object is placed at a distance of 16 cm from it.Find the psition of the image formed by it.

A concave mirror of focal length 25 cm forms the real image of a point object at a distance O lying on its principal axis at a distance of 50 cm from the mirror. The mirror is cut into two halves and are drawn a distance of 1 cm apart in the direction perpendicular to the optical axis .How will the two halves of the concave mirror produce the image of the point object O?

An object is placed in front of a concave mirror of radius of curvature 40 cm at a distance of 10 cm. Find the position and nature of image formed.

If a concave mirror of focal length f produces a real image n times the size of the object,then find the distance of the object from the mirror.

A concave lens is placed in contact with a convex lens of focal length 25 cm.The combination produces a real image at adistance of 80 cm, when an object is at a distance of 40 cm. What is the focallength of concave lens ?

An object is placed in front of a convex mirror of focal length 30 cm.If the image formed is a quarter of the size of the object,find the position of the image.