Question

The ray passing through the _______ of the lens is not deviated.
A. Optical Centre
B. Focus

Answer 1

Hint:In order to answer this question, to know the exact option for the given statement, we will first mention the correct answer and then we will discuss the reason behind the given statement, and then we will discuss more about the correct option.

Complete answer:
The rays passing through the optical centre of the lens pass undeviated. The optical centre of the lens is defined as the point on the major axis through which light rays pass without deflection, or it can be described as the central point of the lens through which light flows without deflection. A ray of light travelling through the optical centre will not change its course. This is a point on the primary axis of a lens through which light passes without deviation.

A ray of light going through the optical centre experiences no refraction, meaning it passes through the centre without deviating. This is due to the fact that it travels through the optical centre perpendicular to the lens's curved surface. As a result, the angle of incidence is zero, and the angle of refraction is zero as well.

Whereas, a focus, also known as an image point in geometrical optics, is a place where light rays originating from a point on the object converge. Although the focus is conceptually a point, it has a spatial extent, which is referred to as the blur circle. Aberrations in the image optics may be to blame for this less-than-ideal focussing.

Hence, the correct option is A.

Note:We merely mean that the incident and emerging rays are parallel to each other when we state there is no deviation. Because the refraction inside narrow lenses is negligible, the ray passing through the optic centre is represented as a straight line.