A concave lens of focal length 15cm forms an image 10cm from the lens. How far is the object placed from the lens? Draw the ray diagram.

A man used a concave lens of focal length 20cm.Find the power of the lens.

An object is placed in front of a concave mirror of focal length 20 cm and an image of magnification -2 is formed. Find the position of the object and the image. Draw a ray diagram.

A convex lens of focal length 20 cm is placed at a distance of 30 cm from a screen. Where should an object be placed so as to form its real image on the screen?

Find the power of a concave lens of focal length 2 m ?

An object of 4 cm height is placed in front of a concave lens. An image of size 2 cm is formed at a distance of 15 an from the lens. Find the object distance and the focal length of the lens.

An object of height 5 cm is placed at a distance of 30 cm from a positive lens whose focal length is 12 cm. Find the position, nature and the size of the image formed. Also, draw a ray diagram.