Optics

Question 1

What is optics?

Answer 1

Optics is the branch of physics that studies light and its behaviour, including how light interacts with objects and how it is manipulated to create images or perform tasks like magnification.

Question 2

Light:

Answer 2

Light is a form of electromagnetic radiation that is visible to the human eye and travels in straight lines.

Question 3

Wave:

Answer 3

A wave is a disturbance that transfers energy from one point to another without transferring matter.

Question 4

Medium

Answer 4

any physical substance (air, water, dust) that acts as a carrier for the transmission of energy.

Question 5

A real image

Answer 5

is produced by real rays and can be projected on a screen.

Question 6

Reflection

Answer 6

Reflection occurs when light bounces off a surface and changes direction, but stays in the same medium.

Question 7

Refraction

Answer 7

Refraction is the bending of light as it passes from one transparent medium to another, due to a change in its speed.

Question 8

Lenses

Answer 8

Lenses are transparent objects made of glass or plastic that refract (bend) light to form images.

Question 9

Plane mirror

Answer 9

Mirror with a flat surface. Images in a plane mirror are always upright and virtual.

Question 10

Spherical Mirrors

Answer 10

Concave and Convex lenses

Question 11

Convex

Answer 11

A convex lens is thicker in the middle than at the edges and converges light rays to a focal point. They only make virtual images They bulge out. Ex. magnifying glass

Question 12

Concave

Answer 12

A concave lens is thinner in the middle than at the edges and diverges light rays. Bulges outward. Ex. car mirror, make up mirror

Question 13

Plane mirror

Answer 13

A straight

Question 14

Focal Point

Answer 14

The focal point is the point at which light rays converge or from which they appear to diverge after passing through a lens.

Question 15

Center of curvature:

Answer 15

The centre of curvature is the point located at the center of the sphere from which a curved mirror or lens is derived.

It’s the point at an equal distance from every point on the mirror or lens, and it defines the curvature of the surface. In simple terms, it’s the point that a mirror or lens would fit into perfectly if it were a part of a complete sphere.

Question 16

Magnification

Answer 16

Magnification is the ratio of the size of an image produced by an optical system to the size of the object.

Question 17

Optical Instruments

Answer 17

Optical instruments are devices that use lenses and mirrors to form images or magnify objects, such as microscopes and telescopes.

Question 18

Dispersion

Answer 18

Dispersion is the separation of white light into its component colours (wavelengths) when it passes through a prism or a material with varying refractive indices for different wavelengths.

Question 19

Incident ray

Answer 19

An incident ray is a ray of light that is pointing towards and striking a surface. An incident ray that is parallel to the principal axis will refract through the focal point.

Question 20

Law of reflection

Answer 20

The angle of incidence is the same as the angle of reflection.
Index of refraction: the larger the index of refraction the smaller the critical angle.

Question 21

Incandescent

Answer 21

light produced by heat ex. light bulb

Question 22

Bioluminescence

Answer 22

light produced by living organisms ex. jellyfish

Question 23

Chemiluminescence:

Answer 23

light produced by a chemical reaction ex. glow sticks

Question 24

Phosphorescence

Answer 24

store energy + emit slowly ex. Glow-in-the-dark stickers

Question 25

Fluorescence

Answer 25

light emitted when exposed to electromagnetic radiation ex. Ultraviolet light

Question 26

Triboluminescence

Answer 26

producing light from friction ex. Biting on wintergreen candy

Question 27

Electric discharge

Answer 27

when an electric current passes through air or another gas ex. lightning]