Revision topic 10

Question 1

what the normal ray

Answer 1

the line premedical to the mirror

Question 2

what is the law of reflection

Answer 2

the angle of incident = the angle of reflection

Question 3

what is the angle of incident

Answer 3

it is the angle between the normal and the incident ray

Question 4

what is the angle of reflection

Answer 4

it is the angle between the normal and the reflected ray

Question 5

what is a virtual image

Answer 5

an image formed by the mirror, it cannot be projected on the screen

Question 6

what is a real image

Answer 6

it is an image formed by focusing light rays into the screen

Question 7

what is refraction

Answer 7

it is the change of direction of travel of waves when they cross over a boundary from one medium to another

Question 8

what is the rule of refraction

Answer 8

1. when light enters a more dense medium its refracted towards normal
2. when light enters a less dense medium it is refracted away from normal

Question 9

how can you investigate refraction

Answer 9

by getting a ray box and shooting it into a glass bock then comparing the angle of the incident with the angle of refraction
the results would show:
1. from air to glass the refractive angle would refract towards normal causing the incident angle to be larger than the angle of refraction
2. from glass to air the refractive angle would reflect away from normal, so the angle of refraction would be bigger than the angle of reflection

Question 10

what is dispersion

Answer 10

the splitting of white light into the colors of the spectrum by using a prism

Question 11

what would happen if light passes through the glass from air

Answer 11

1. the angle of the incident would always be greater than the angle of refraction
2. the greater the angle of incident is, the greater the angle of reflection is

Question 12

what is snells law

Answer 12

snell’s law state that angle of incident/ angle of reflection would always have the same value for the same medium that the block is made of regardless of the incident angle

Question 13

refractive index =

Answer 13

sin i / sin r or speed of the light in the vacuum/speed of the light in the medium

Question 14

what happens if you keep increasing the angle of incident

Answer 14

if you keep increasing the ingle of the incident you would keep increasing the angle of refraction until it emerges on the boundary, when that happens the angle of the incident would become the critical angle, if you increase the incident angle beyond the critical angle you would have total internal reflection, where the angle of the incident would be equal to the angle of refraction

Question 15

what is the formula for the critical angle

Answer 15

sin c = 1/refractive index

Question 16

what is the endoscope and how is it used

Answer 16

the endoscope is used by surgeons s to see inside the body. the endoscope contains two buddles of optical fibers one shine light on the captivity and the other and the other transmit back the light for the doctors to see, which either can be seen in an image or directly by the doctors, other than that the surgeons can use its energy for laser treatments, as for example, they can use it to seal off blood vessels or kill damaged cells