A Short Note on Rays Not Parallel to Principal Axis

Axis lines in physics are demonstrated as an imaginary or real line on which something rotates or a direct line around which certain things are evenly structured. The instance of the axis is mentioned as an imaginary line that is continuing through the earth on which rotation of the earth is seen. Parallel rays are mentioned as two rays that are parallel if the communicative line determined and recognised by them is parallel. In physics, the instance of the passing of light rays has been considered. The focal point of light rays gets deviated and refracted when the “parallel rays” of the light have passed through a “concave lens to the principal axis”. All the rays are parallel to the “principal axis” of the concave mirror that gets intersected at a specific point which is demonstrated as the principal focus.

Concept of Axis

The principal axis is demonstrated as the optical axis of the lens that proceeds through the centre of optics of the lens. The principal axis is demonstrated as the line that is moving and progressing through the curvature centre of the lens faces or a curved mirror. Axis of rotation is determined if a “perpendicular line to the plane is imagined where the tough body is moving and revolving. The principal axis of any specified object is demonstrated as the rotation axis of the body that suffices, which is also demonstrated as a three-dimensional body. The Axis of rotation possesses significant distinction from the rotation point where the axis is measured as 90 degrees. In the principal axis, the three mutually axes are perpendicular concerning which the inertia moment of a body tends to be maxima. The principal axes of the rigid body inertia are referred to as the axes set that pass through the centre of mass of an object and are concerned with the mass distribution of the object. 

Facts of parallel rays

• Parallel rays are mentioned as the two rays that are parallel if the interactive lines demonstrated are parallel. The two rays in a similar plane are referred to as parallel if the intersection of two rays does not occur even if they expanded indefinitely beyond their “primary points”.
• Parallel rays never come after the other differentiates parallel lines from the other lines that are non-meeting. Parallel rays bundle are parallel to the other which is termed a “parallel light beam”.
• The rays from infinity are regarded as parallel because the wave fronts’ curves get nearly straight. The rays of light are mentioned to be normally coming down on the curves and as with the maximised length, the curves get nearly straight. In this context, the light rays are predicted to be parallel.

Rays not parallel to the principal axis

Predicting that the light is impending from the infinity and rays of light are not parallel to the principal axis. Then the light that tends to pass through the lens seems to bend parallel to the “principal axis”. It means that when the rays of light are impending from infinity are placed at a particularised point beyond the lens. All the rays of light in this context are bent exactly parallel to the principal axis and the point is also known as the “focal point”.  The rays are not parallel to the lens’ parallel axis which passes through and diverges after the refraction. It is always assumed that when the ray passes through the principal axis, one light ray becomes parallel which tends to pass through different axes.

Conclusion

It is like the angular momentum transmitted regarding the principal axis which is not conveyed to any other axis. Principal stress axes are demonstrated as normal to the zero planes shear stress where the principal axes are regarded as orthogonal. The maximum shear stress of the principal axis is around 45 degrees from the direction of principal stress. The maximum shear stress is regarded as one and a half the distinction of the principal stress. A principal plane is demonstrated as the stress property whereas the principal axis is mentioned as the property of inertia moment. The principal axis and normal are almost similar in the spherical mirror.