A point object O is placed in front of a glass rod having a spherical end of radius of curvature 30 cm. The image would be formed at :
An object is placed 18 cm in front of a spherical mirror. If the image is formed at 4 cm to the right of the mirror then calculate its focal length. Is the mirror concave or convex. What is the nature of the image. What is the radius of curvature?