Optics

Question 0

Non-luminous object

Answer 0

Does not produce its own light, reflects light from its surface which makes it visible

Question 1

Self luminous object

Answer 1

Produces its own light e.g. Sun

Question 2

Reflection

Answer 2

The bouncing of light off the surface of an object

Question 3

Laws of reflection

Answer 3

1. The incident Ray, the normal and the reflected Ray all lie in the same plane
2. The angle of incidence equals the angle of reflection

Question 4

Parallax

Answer 4

The apparent movement of one object relative to the other due to the motion of the observer

Question 5

Real image

Answer 5

Formed by the actual intersection of light rays

Question 6

Virtual image

Answer 6

Formed by the apparent intersection of light rays

Question 7

Refraction

Answer 7

The bending of light as it passes from one optical medium to another

Question 8

Laws of refraction

Answer 8

1. The incident Ray, the normal and the refracted Ray all lie in the same plane
2. (Snell’s law) sini/ sinR= n which is a constant

Question 9

The critical angle

Answer 9

The angle in the denser of the two media when the angle in the less dense medium is 90 degrees

Question 10

Total internal reflection

Answer 10

When the angle of incidence in the denser of two media exceeds the critical angle and light is reflected back into the medium

Question 11

Optic fibre

Answer 11

A very thin strand of transparent material through which light travels by total internal reflection

Question 12

The power of accommodation

Answer 12

The eyes ability to focus on objects at different distances by changing the shape of the lens