When an object is kept in front of a concave mirror of a focal length of 10 cm, a real image is formed at a distance of 20 cm in front of the mirror. Here, the object distance is .............
− 20 cm
The correct answer is option 4 i.e. − 20 cm.
To find the object distance (u) for a concave mirror, we use the mirror formula:
1/f=1/v + 1/u
Given:
-
Focal length (f) = –10 cm (negative for concave mirror)
-
Image distance (v) = –20 cm (real image formed in front of the mirror)
Now, substitute values:
1/−10 =−1/−20 + 1/u
u/1=−1/−10 −1/−20 = −1/10 + 1/20 = −1/20
u = −20 cm
Similar Questions
- If an object is placed between infinity and the pole (P) in front of a convex mirror, what type of image will be formed?
- A concave mirror produces three times magnified (enlarged) real image of object placed at 10 cm in front of it. Which option describes the image correctly?
- Which of the following mirrors is used by doctors to focus a parallel beam of light on the patient's organs like teeth for the examination?
- The radius of curvature of a spherical mirror is 20 cm. Its focal length is:
- The nature of the image formed by a concave mirror if the magnification produced by the mirror is +3 is:
Important Questions from Mirrors and Images
Which one of the following telescopes contains only mirrors?
The correct relation between the radius of curvature R and focal length f of a spherical mirror is
Spherical mirror formula relating an object distance ‘u’, image distance ‘v’ and focal length of mirror ‘f’ may be applied to a plane mirror when
The image of an object formed by a plane mirror is
The image we see in plane mirror is
