Light (10)

Question 1

First law of reflection

Answer 1

The incident ray, reflected ray, and the normal lie on the same plane

Question 2

Second law of reflection

Answer 2

In reflection, the angle of incidence is equal to the angle of reflection

Question 3

Reflected image and characteristics

Answer 3

Formation of image in a plane mirror due to the reflection of light
1. Virtual (An image that cannot be captured on a screen)
2. Erect/Upright
3. Same size as object
4. Same distance from the mirror as object
5. Laterally inverted

Question 4

Refraction

Answer 4

Bending of light as light passes from one optical medium to another, due to light changing speed

Question 5

First law of refraction

Answer 5

The incident ray, refracted ray, and the normal lie on the same plane

Question 6

Second law of refraction

Answer 6

For two given media, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant (refractive index)

Question 7

Refractive index

Answer 7

Refractive index of a medium is the ratio of the speed of light in vacuum (or air) to the speed to light in the medium

Question 8

Critical angle

Answer 8

Angle of incidence which gives rise to an angle of refraction of 90 degrees (Only takes place when light travels from a denser to less dense medium)

Question 9

Lens

Answer 9

A transparent material to refract (or bend) the light rays as a way to form an image. It refracts light rays when they pass through it

Question 10

Principal axis

Answer 10

A straight line which passes through the centre of the lens at a right angle to the plane of the lens

Question 11

Principal focus

Answer 11

A point on the principal axis in which the incident rays travelling parallel to the principal axis converge or diverge after refraction through the lens

Question 12

Focal length

Answer 12

The distance between the centre of the lens and the principal focus

Question 13

Real image

Answer 13

An image that can be captured on the screen