As an object is moved from the surface of a thin converging lens to a focal point, over what range does the image distance very?

A luminous object is placed at a distance of 40 cm from a converging lens of focal length 25 cm. The image obtained in the screen is

An object is placed at the focus of concave lens having focal length /. What is the magnification and distance of the image from the optical centre of the lens ?

A point object is placed at a distance of 20cm from a thin plano-convex lens of focal length 15cm If the plane surface is silvered.the image will form at

An object is placed at a distance of 100 cm from a converging lens of focal length 40 cm. i) What is the nature of image? ii) What is the position of image?

Choose the correct alternative corresponding to the object distance 'u', image distance 'v' and the focal length 'F' of a converging lens from the following . The average speed of the image as the object moves with the uniform speed from distance (3F)/(4) to (F)/(2) is greater than the average speed of the image as the object moves with same speed from distance (F)/(2) "to" (F)/(4) The minimum distance between a real object and its real image in case of a converging lens is 4F where F is its focal length.

Choose the correct alternative corresponding to the object distance 'u', image distance 'v' and the focal length 'F' of a converging lens from the following . The average speed of the image as the object moves with the uniform speed from distance (3F)/(4) to (F)/(2) is greater than the average speed of the image as the object moves with same speed from distance (F)/(2) "to" (F)/(4) The minimum distance between a real object and its real image in case of a converging lens is 4F where F is its focal length.

An illuminated object is placed at a distance of 20 cm from a converging lens of focal length 15 cm. The image obtained on the screen is: