Ch 12

Question 1

Spherical mirror

Answer 1

A mirror whose polished reflecting surface is a part of hollow sphere or glass or plastic

Question 2

Pole

Answer 2

It is the midpoint of curved surface

Question 3

Centre of curvature

Answer 3

Centre of sphere

Question 4

Radius of curvatur

Answer 4

Radius of the sphere

Question 5

Principal focus

Answer 5

Concave
Rays of light parallel to principal axis converge to point f
Convex
Appear to come from point f

Question 6

Focal length

Answer 6

Distance from the pole to the principal focus

Question 7

Focus concave and convex

Answer 7

Convex lies behind mirror
Virtual
Concave
Front of the mirror
Real

Question 8

Mirror formula

Answer 8

The relationship between object dis imag dis and focal length
1/d=1/p+1/q

Question 9

Snell law

Answer 9

The ration of sine of angle of I to sine of angle of r is equal to constant

Question 10

Refractive index

Answer 10

Ratio of speed of light in air c to speed of light in medium v
N=c/v

Question 11

Total internal reflection

Answer 11

Angle of I becomes larger than CA no refraction occurs all light is reflected back in denser medium

Question 12

Angle of deviation

Answer 12

The angle through which the ray of light is deviated from original path after passing through prism

Question 13

Power of lens

Answer 13

Reciprocal of focal length
Dioptre

Question 14

Resolving power

Answer 14

Instrument is its ability to distinguish between two closely placed objects