light

Question 1

refraction

Answer 1

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

Question 2

snell’s law

Answer 2

for two given mediums, the ratio of the sine of the angle of incidence i to the sine of the angle of refraction r is a constant given by sini/sinr=constant

Question 3

refractive index

Answer 3

ratio of speed of light in vacuum to speed of light in the medium

Question 4

critical angle

Answer 4

angle of incidence in the optically denser medium for which the angle of refraction in the optically less dense medium is 90°, given by c=sin-1(1/n)

Question 5

total internal reflection

Answer 5

complete reflection of a light ray inside an optically denser medium at its boundary with an optically less dense medium (occurs when angle of incidence i in the optically denser medium is greater than critical angle c in the medium)

Question 6

principal axis

Answer 6

horizontal line passing through optical centre c of the lens and is perpendicular to vertical plane of the lens

Question 7

optical centre c

Answer 7

midpoint between surface of lens on its principal axis

Question 8

focal point F

Answer 8

point at which all rays parallel to the principal axis converge to after refraction through the lens

Question 9

focal plane

Answer 9

the plane that passes through the focal point F and is perpendicular to the principal axis

Question 10

focal length

Answer 10

distance between focal point F and optical centre C of the lens