Explain the following terms with the help of a diagram.
a. Centre of curvature
b. Focus
c. Focal length
d. Vertex
e. Principal axis
Answers
Answer:
Centre of curvature :
the centre of a circle which passes through a curve at a given point and has the same tangent and curvature at that point.
Focus :
When rays from infinity come in parallel to the optical axis of a spherical mirror, they are bent so that they either converge and intersect in at a point, or they seem to diverge from a point. The point of convergence or divergence is called the focus.
Focal Length :
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative focal length indicates that the system diverges light.
Vertex :
The point on the mirror's surface where the principal axis meets the mirror is known as the vertex and is denoted by the letter A in the diagram below. The vertex is the geometric center of the mirror.
Principal axis :
The principal axis is called a line that passes via the centre of the surface of a spherical mirror or lens and through the centre of curvature of all segments of the mirror or lens.
Explanation:
the correct answer is centre of curvature