B. Magnification M? A small linear object of length b is placed at a distance u from the pole of the concave mirror along the axis the focal length of mirror is f. The length of image will be. Solution: The radius of curvature of the mirror = 30 cm Thus, the focal length of the mirror =\(\frac { 30 cm }{ 2 } \) = 15 cm. From mirror formula 1 / f = 1 / u + 1 / v Where f is focal length u is object distance v is image distance 1 / f = 1 / u + 1 / v 1 / 6 = 1 / 9 + 1 / v 1 / v = 1 / 6 - 1 / 9 1 / v = 1 / 18 Take reciprocal of both sides v = 18 cm Since the image distance is positive, then, the image is real. In diagram, PF is the focal length of the mirror. Solution: We have u = –15 cm and f = –10 cm We'll subtract that 2 inches from the distance between the tertiary mirror and the focal plane to determine the distance b so we end up with 6.5 inches for the distance. Focal length. Principal section. ... Write down the magnification formula for a lens in terms of object distance and image distance. Incident rays parallel to the optical axis are reflected from the mirror and seem to originate from point \(F\) at focal length \(f\) behind the mirror. Magnification can be determined using The mirror equation expresses the quantitative relationship between the object distance (d o), the image distance (d i), and the focal length (f). A convex spherical mirror also has a focal point, as shown in Figure \(\PageIndex{3}\). The lens equation has to do with the projected image, the distances between objects, the shape of the lens and focal length, which you … 5 cm needle is placed 12 cm away from a convex mirror of focal length 15 cm. Thus, the distance A ends up being: It is represented by the symbol f. For mirrors of small aperture, f=R/2. h … Give the location of the image and the magnification. The distance between the pole and the principal focus of the mirror, is called the focal length of the mirror. HARD. The distance along the optical axis from the mirror to the focal point is the focal length f of the mirror. With a magnification of 3 and the effective focal length of 90 inches which will make it an F10 system. Find the position of the image. Example 4: An object is placed at a distance of 15 cm from a concave mirror of focal length 10 cm. solution. The magnification equation relates to the distance and height of an image or object and defines what M is, which is magnification. The equation is stated as follows: The magnification equation relates the ratio of the image distance and object distance to the ratio of …