What happens to parallel rays near the principal axis in a spherical mirror?
They reflect and meet, or appear to meet, at a single point.
What is the principal focus?
The point where reflected rays intersect or appear to intersect.
When is the principal focus real?
When reflected rays actually meet at the focus.
When is the principal focus virtual?
When reflected rays only appear to diverge from the focus.
What happens if a screen is placed at a real focus?
A clear image is formed.
What happens if a screen is placed at a virtual focus?
No image is formed.
What is focal length?
The distance from the pole to the principal focus.
What is the relationship between radius of curvature and focal length?
r=2f
What is another form of the relationship between r and f?
f= r / 2
Does this relationship apply to both concave and convex mirrors?
Yes, it applies to both.
What is the purpose of a spherical mirror?
To change the direction of light rays and alter the curvature of the wavefront.
What determines the image formed by a spherical mirror?
The type of mirror and the position of the object.
What image properties are affected?
Position, size, and nature of the image.
What are the two methods used to find image position and size?
Graphical construction and analytical methods.
What is the graphical construction method?
A scale drawing method using construction rays.
What is special about construction rays?
They follow predictable paths after reflection.
How are spherical mirrors represented in diagrams?
As straight lines with markings to show concave or convex.
What does point A represent?
The pole or vertex.
What does point C represent?
The centre of curvature.
What does point F represent?
The principal focus.
What determines how images form in concave and convex mirrors?
The position of the object and the type of mirror.
What happens to rays in a concave mirror?
They can converge to form real images.
What happens to rays in a convex mirror?
They diverge and form virtual images.
What is the analytical method?
A method using calculations to determine image position and size.
