Advertisements
Advertisements
प्रश्न
The refractive index of glass is 1.5. From a point P inside a glass block, draw rays PA, PB and PC incident on the glass air surface at an angle of incidence 30°, 42° and 60° respectively.
- In the diagram show the approximate direction of these rays as they emerge out of the block.
- What is the angle of refraction for the ray PB?
`("Take" sin 42° =2/3)`
Advertisements
उत्तर
- A diagram with rays PA, PB and PC is shown below:
- Given, μ = 1.5
As we know,
`sin i_c = 1/mu`
substituting the values in the formula, we get,
`sin i_c = 1/1.5`
sin ic = 0.667
ic = 41.8
Hence, we can round off ic = 42°
Applying `sin r/sin i = ""_amu_g`
sin r = `""_amu_g xx sin i`
sin r = `""_amu_g xx sin 42°`
Given, sin 42° = `2/3`
and `""_amu_g = 3/2`
substituting the value in the formula, we get,
`sin r = 3/2 xx 2/3`
sin r = 1
As sin r = 1, the angle of refraction is 90°.
APPEARS IN
संबंधित प्रश्न
Draw the diagram given below and clearly show the path taken by the emergent ray.
For which colour of white light, is the refractive index of a transparent medium the most?
A ray of light is passing from a transparent medium 1 to another transparent medium 2 (i) Speed up (ii) slows down. In each case, state whether the refractive index of medium 2 is equal to, less than or greater than the refractive index of medium 1.
Four students A, B, C and D traced the paths of incident ray and the emergent ray by fixing pins P and Q for incident ray and pins R and S for emergent ray for a ray of light passing through a glass slab.
The correct emergent ray was traced by the student:
(1) A
(2) B
(3) C
(4) D
What is the correct reason for blinking / flickering of stars? Explain it.
a) The blasts in the stars.
b) Absorption of star light by the atmosphere.
c) Motion of the stars.
d) Changing refractive index of gases in the atmosphere.
In the fig. name the ray which represents the correct path of light while passing through a glass block.
Fig shows a lens as a combination of a glass block and two prisms.
(i) Name the lens formed by the combination.
(ii) What is the line XX' called?
(iii) Complete the path of the incident ray PQ after passing through the lens.
(iv) The final emergent ray either meets XX' at a point or appears to come from a point on XX'. Label it as F, What is this point called?
Name the phenomenon responsible in the following case:
Apparent bending of a stick in water
Name one main factor on which the direction of bending of a ray of light depends.
