Question

When an object moves closer to a concave lens the image formed by it shifts
a) away from the lens
b) first away and then towards the lens
c) towards the lens
d) first towards and then away from the lens

Answer 1

In a concave lens, when the object is located at infinity, the image is made at the lens's focus, and if the object goes closer to the concave lens, the image is also transferred from its focus toward the lens size increment. Thus, the image is moved away from its focus towards infinity as the object goes from infinity towards the concave lens's center.

Complete answer:
A concave lens is a lens that deviates a straight light beam from the origin to a diminished, erect, virtual image. Concave lenses possess at least one surface curled inside. A concave lens is identified as a diverging lens because it is formed around inwards at the center and swells outwards through the corners, making the light deviate. They are utilized to treat myopia as they obtain faraway objects that look tinier than they are.
The concave lens is the diverging lens because it deviates the rays after they move through it; the image made by the concave lens is virtual because it cannot be obtained on a screen.
In a concave lens, when the object is positioned at infinity, the image is made at the lens's focus, and if the object travels closer to the concave lens, the image is also transferred from its focus toward the lens size rise. A concave lens always presents a virtual image. It can never make an actual image. The image is continuously formed on the same surface of the lens as the object, thus can be viewed in the lens only.
Therefore, Option (a) is correct.

Note: Lenses made by binding two spherical exteriors bulging outside are known as convex lenses, while the lenses made by binding two spherical outsides such that they are curved inward are named concave lenses. Convex lenses are also recognized as converging lenses since the rays concentrate after falling on the convex lens, while the concave lenses are named diverging lenses as the rays deviate after falling on the concave lens.