Light – Reflection and Refraction

Flashcards covering key concepts from the Principles of Light – Reflection and Refraction.

What makes objects visible to us in a room?

Light reflects off objects, allowing our eyes to detect them.

What direction does light appear to travel?

Light appears to travel in straight lines.

What is diffraction of light?

Diffraction occurs when light bends around a small object in its path.

What does the wave theory of light suggest?

Light behaves like a wave when interacting with matter.

What is meant by the principal focus of a concave mirror?

The point where parallel rays converge after reflection.

What are the laws of reflection?

(i) Angle of incidence = Angle of reflection; (ii) incident ray, normal, and reflected ray are in the same plane.

What type of image is formed by a plane mirror?

The image is virtual, erect, laterally inverted, and equal in size to the object.

Define concave mirror.

A mirror with a reflecting surface that curves inward.

Define convex mirror.

A mirror with a reflecting surface that curves outward.

What is the centre of curvature in a spherical mirror?

The center of the sphere from which the mirror is a part.

What is the radius of curvature in a spherical mirror?

The radius of the sphere of which the mirror is a part.

What is the principal axis of a spherical mirror?

A straight line passing through the pole and the centre of curvature.

What is the focus of a concave mirror?

The point on the principal axis where light rays converge.

How is focal length related to the radius of curvature in spherical mirrors?

Focal length (f) = Radius of curvature (R) / 2.

What is the nature of an image formed by a concave mirror when the object is beyond C?

The image is real and inverted.

What happens to the image size when the object is placed between F and C in a concave mirror?

The image is enlarged and real.

What type of image does a convex mirror always produce?

Virtual, erect, and diminished.

What is the New Cartesian Sign Convention for spherical mirrors?

Object is left of the mirror, distances to right are positive, and distances above the principal axis are positive.

What is the mirror formula?

1/f = 1/v + 1/u.

What does magnification indicate in mirrors?

The ratio of image height to object height.

What is the power of a lens?

The reciprocal of its focal length, measured in diopters.

What does a positive power of a lens indicate?

The lens is converging (convex lens).

What does a negative power of a lens indicate?

The lens is diverging (concave lens).

What does Snell's law relate?

The ratio of sine of angle of incidence to sine of angle of refraction.

Define refraction of light.

The bending of light when it passes from one medium to another.

What occurs when light travels from a denser to a rarer medium?

The light bends away from the normal.

What is the refractive index?

The ratio of speed of light in vacuum to speed of light in a medium.

What is a lens?

A transparent material that bends light, usually with spherical surfaces.

What happens when parallel light rays pass through a convex lens?

The rays converge at the principal focus on the opposite side.

What is the result when parallel light rays pass through a concave lens?

The rays appear to diverge from a virtual focus on the same side as the object.

What is the image formed by a concave lens?

Virtual, erect, and diminished.

How can the focal length of a convex lens be determined?

By focusing sunlight onto a paper to form a sharp image.

What is the magnification formula for lenses?

m = h'/h = v/u.

What is the aperture of a lens?

The effective diameter of the lens's circular outline.

What is the nature of the image formed by a lens when the object is placed at infinity?

The image is highly diminished, real, and point-sized.

Where should an object be placed to get a real image of the same size in a convex lens?

At twice the focal length.

What type of mirror is used as a rear-view mirror?

Convex mirror due to its erect and wider field of view.

What happens to the image size when the object is placed far away from a concave lens?

The image remains virtual, erect, and diminutive.

What is the relationship between the object distance and image distance for lenses?

They are related by the lens formula.

What happens to light rays passing through the optical center of the lens?

They pass through without deviation.

What is a real image?

An image formed where light rays converge and can be projected on a screen.

What is a virtual image?

An image formed where light rays appear to diverge, cannot be projected on a screen.

How does the focal length affect the power of a lens?

Shorter focal lengths have higher power.

What is the characteristic of the image formed by a convex mirror?

Always virtual and diminished.

What happens to light in a denser medium compared to a rarer medium?

Light slows down and bends towards the normal.

How do lenses form images?

By refracting light rays that pass through them.

What occurs to the apparent position of objects in water?

They appear raised due to refraction.

What is represented by F in lens diagrams?

The principal focus of the lens.

What type of image does a concave mirror produce when the object is between the focus and the mirror?

The image is virtual, enlarged, and erect.

Describe the ray diagram for a convex lens and object beyond 2F.

Image formed between F2 and 2F2, real and diminished.

What do you observe through a concave lens when viewing an object?

The image appears erect and smaller.