A convex lens produces a double size real image when an object is placed at a distance of 18 cm from it. Where should the object be placed to produce a triple size real image ?

A convex lens produces a real image double the size of the object, when the object is placed at a distance 18 cm from it. Where should the object be placed to produce a real image three times the size of the object?

A concave mirror produeces a real image of magnificaion 1//2 ,when an object is placed at a distance of 60 cm from it.Where should the object be placed ,so that a virtual image of double the size is formed by the miror?

A convex lens produces a real image m times the size of the object. What is the distance of the object from the lens ?

A convex lens produces a real image m times the size of the object. What will be the distance of the object from the lens ?

A convex lens produces a real image m times the size of the object. What will be the distance of the object from the lens ?

A convex lens from a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle be placed in front of the convex lens if the image is equal to size of the object? Also, find the power of the lens?