When an object is placed at a finite distance from a concave lens, the image formed is always:

Question

Examoogle · Accepted Answer

The correct answer is Option C: Virtual and diminished. A concave lens is a diverging lens that always forms a virtual, erect, and diminished image for any object placed at a finite distance. Regardless of the object's position, the refracted rays appear to diverge from a point between the optical center and the focus.

Step-by-Step Solution & Concepts:
A concave lens is a diverging lens that always forms a virtual, erect, and diminished image for any object placed at a finite distance. Regardless of the object's position, the refracted rays appear to diverge from a point between the optical center and the focus.

Working Principle: When light rays parallel to the principal axis strike a concave lens, they diverge after refraction. Since these rays never actually meet, they are traced back to form a virtual image on the same side of the lens as the object. According to the lens formula $\frac{1}{v} - \frac{1}{u} = \frac{1}{f}$, for a concave lens, the focal length $f$ is negative, ensuring that the image distance $v$ remains negative, resulting in a virtual image.

Key Formulas: $\frac{1}{v} - \frac{1}{u} = \frac{1}{f}$ — Lens formula where $u$ is object distance, $v$ is image distance, and $f$ is focal length; $m = \frac{v}{u}$ — Magnification formula where $m

Key Points: Concave lenses always produce virtual images.; The image formed is always upright (erect).; The image size is always smaller than the object size.; Concave lenses are used to correct myopia (nearsightedness).

Advantages: Useful for correcting vision defects like myopia; Provides a wider field of view

Disadvantages: Cannot be projected onto a screen because the image is virtual

Applications: Spectacles for nearsightedness; Peepholes in doors; Beam expanders in laser instruments

Additional Info: For a concave lens, the focal length $f$ is always taken as negative by the sign convention.. Option A is incorrect because real images cannot be formed by a single concave lens.. Option B is incorrect because the image is diminished, not magnified.. Option D is incorrect because the image size is never the same as the object size for a concave lens.

Answer: C is correct — A concave lens always produces a virtual, erect, and diminished image irrespective of the object's distance.

Exam Tip: Remember that convex mirrors and concave lenses share the same image characteristics: they both always form virtual, erect, and diminished images.

Examoogle · Answer

Option A: Real and inverted

Examoogle · Answer

Option B: Virtual and magnified

Examoogle · Answer

Option D: Real and same size

Correct Answer

Discussion (0)

Correct Answer

Related Questions

Discussion (0)