What will be the sign of the object distance for a concave lens?

Correct option is A

The correct answer is option (a) Negative.

Explanation

In the case of a concave lens, the object distance is always considered negative. This is because for a concave lens, the object is always positioned in front of the lens (on the same side as the incoming light), and according to the sign conventions used in optics, object distances in front of the lens are taken as negative.

Information Booster

• In optics, the sign convention states that distances measured against the direction of light (on the same side as the incoming light) are considered negative, while distances measured along the direction of light (on the opposite side) are positive.

• For a concave lens, the object is always placed in front of the lens, and the light diverges, so the object distance is always negative.

Additional Knowledge

1. Positive: The object distance for a concave lens is not positive. It is negative according to the sign convention in optics.

2. Sometimes positive, sometimes negative: The object distance for a concave lens is not variable; it is consistently negative.

3. It depends on the object distance from the lens: The object distance for a concave lens always follows the sign convention and is consistently negative.