CH6

Question 1

Definition of refraction of LIGHT

Answer 1

Light changes direction as it travels through medium of different optical densities

Question 2

Change in Velocity & Direction of Light from high optical density to low optical density

Answer 2

Velocity Increases
Light ray is refracted away from normal

Question 3

Change in Velocity & Direction of Light from low optical density to high optical density

Answer 3

Velocity decreases
Light ray is refracted towards normal

Question 4

Definition of refractive index

Answer 4

Ratio of speed of light in vacuum to speed of light in medium

Question 5

Relationship between refractive index and
1. Speed of light in medium
2. Optical density

Answer 5

1. The slower speed of light in medium, the higher the optical density
2. The higher the optical density, the higher the refractive index

Question 6

Snell’s Law

Answer 6

When light travels from one medium to another medium, the incident ray,
the refracted ray and the normal meet at one point and are in the same
plane

Question 7

Definition Of Critical Angle

Answer 7

Incident angle of medium of higher optical density when refraction angle of medium of lower optical density equal to 90°

Question 8

Definition of Total Internal Reflection

Answer 8

A phenomenon when light travels from medium with higher optical density to medium with lower optical density where the incidence angle is greater than Critical angle

Question 9

Refracted and reflected ray when Incidence angle < Critical angle

Answer 9

Refracted ray bends away from normal
Weak reflected ray

Question 10

Refracted and reflected ray when Incidence angle = Critical angle

Answer 10

Refracted ray travels along the boundary

Stronger reflected ray

Question 11

Refracted and reflected ray when Incidence angle > Critical angle

Answer 11

Total internal reflection
No reflected ray

Question 12

Definition of Optical centre, O

Answer 12

Point at the centre of the lens

Question 13

Definition of Principle axis of lens

Answer 13

Straight line through the optical centre of a lens and the centre of
curvature of both surfaces of the lens

Question 14

Definition of Axis of lens

Answer 14

Straight line through the optical centre and perpendicular to the principal
axis

Question 15

Definition of Focal point, F of lens

Answer 15

Point located at the principle axis of a lens where light rays parallel to the principal axis is converged at or appear to be diverged from after passing through the lens

Question 16

Definition of Object distance, u

Answer 16

Distance between object and optical centre of a lens or pole of spherical mirror

Question 17

Definition of Image distance, v

Answer 17

Distance between image and optical centre of a lens or pole of spherical mirro

Question 18

Definition of Focal length, f

Answer 18

Distance between focal point, F and optical centre, O of a lens or pole of spherical mirror

Question 19

Definition of Linear magnification, m

Answer 19

Ratio of image height to object height = ratio of image distance to object
distance

Question 20

Definition of Centre or curvature, C

Answer 20

Centre of sphere which produces a concave or convex mirror

Question 21

Definition of Radius of curvature of
mirror, r

Answer 21

Distance between the pole of spherical mirror,P and the centre of
curvature, C

Question 22

Definition of Focal point, F of spherical mirror

Answer 22

A point on the principal axis of the spherical mirror where light rays parallel to the principal axis are converge at or appear to diverge from

Question 23

Definition of Principal axis of spherical mirror

Answer 23

Straight line passing through the centre of curvature, C and pole of the
spherical mirror