In Your Laboratory You Trace the Path of Light Rays Through a Glass Slab for Different Values of Angle of Incidence (∠i) and in Each Case Measure the Values of the Corresponding Angle of Refraction (∠r) and Angle of Emergence (∠e) - Science

Advertisements
Advertisements

In your laboratory you trace the path of light rays through a glass slab for different values of angle of incidence (∠i) and in each case measure the values of the corresponding angle of refraction (∠r) and angle of emergence (∠e). On the basis of your observations your correct conclusion is:

(a) ∠i is more than ∠r, but nearly equal to ∠e

(b) ∠i is less then ∠r, but nearly equal to ∠e

(c) ∠i is more than ∠e, but nearly equal to ∠r

(d) ∠i is less than ∠e, but nearly equal to ∠r

Advertisements

Solution

(a) ∠i is less than ∠r but nearly equal to ∠e.

On entering a glass slab, the incident light gets refracted. According to Snell’s law, we get

`mu=sini/sinr`

For glass μ > 1

∴sinr < sini

or r < i

In refraction of light through a glass slab, the emergent ray is parallel to the incident ray. Thus, ∠i = ∠e.

  Is there an error in this question or solution?
2015-2016 (March) All India Set 3

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

When a ray of light travels from air to glass slab and strikes the surface of separation at 90°, then it …………….
(a) bends towards normal
(b) bends away from normal
(c) passes unbent
(d) passes in zigzag way


Explain how spectrum is formed.


When rays of light are incident on a glass slab then the incident ray and emergent ray are _________ each other.

  1. perpendicular
  2. parallel
  3. opposite
  4. concurrent

What is a spectrum?


Choose the correct alternative and rewrite the following sentence.

A ray of light strikes the glass slab at an angle of 50°. What is the angle of incidence?


Write a short note on dispersion of light.


Define refraction and state the laws of refraction.


Explain how the formation of a rainbow occurs.


A student traces the path of a ray of light through a rectangular glass slab for the different values of angle of incidence. He observes all possible precautions at each step of the experiment. At the end of the experiment, on analyzing the measurements, which of the following conclusions is he likely to draw?

(A) ∠i = ∠e < ∠r

(B) ∠i < ∠e < ∠r

(C) ∠i > ∠e > ∠r

(D) ∠i = ∠e > ∠r


If the speed of light in vacuum is 3 × 108 ms−1, find the speed of light in a medium of absolute refractive index 1.5.


On the basis of the experiment, "To trace the path of a ray of light through a rectangular glass slab", students of a class arrived at which one of the following conclusions?

(A) Angle of incidence is greater than the angle of emergence.

(B) Angle of emergence is smaller than the angle of refraction.

(C) Emergent ray is parallel to the refracted ray.

(D) Incident ray and emergent ray are parallel to each other.


Why do we get a spectrum of seven colors when white light is dispersed by a prism?


Explain the term absolute refractive index of a medium and write an expression to relate it with the speed of light in vacuum.


Draw a ray diagram to show the refraction of a monochromatic ray through a prism when it suffers minimum deviation


Draw the diagram of refraction of light in the glass slab


Why is the ratio of the velocities of light of wavelengths 4000Å and 8000Å in vacuum 1: 1?


Observe the following figure and answer the questions given under it:

1) How many times does refraction take place in the above figure?

2) What happens to the ray of light when it passes from air to glass?

3) What happens to the ray of light when it passes from glass to air?

4) What are the rays AB and CD in the figure called?

5) Define refraction.


 How must light travel out of a substance if it is not going to be refracted? 


How does the refractive index of a medium depend on the wavelength of light used? 


What is a prism?
With the help of diagram of a prism, indicate its refracting surfaces, refracting edge and base. 


State one advantage of using a total reflecting prism as a reflector in place of plane mirror. 


Which of the following is the best experimental set-up out of the four shown for tracing the path of a ray of light passing through a rectangular glass slab ?


After tracing the path of rays of light through a glass slab for three different angles of incidence, a student measured the corresponding values angle of refraction r and angle of emergence e and recorded them in the table given below: 

S. No.

i

i

e

I

30°

20°

31°

II

40°

25°

40°

III

50°

31°

49°

The correct observations are:

(A) I and II

(B) II and III

(C) I and III

(D) I, II and III


Four students showed the following traces of the path of a ray of light passing through a rectangular glass slab.

 

The trace most likely to be correct is that of student

(A) I

(B) II

(C) III

(D) IV


While performing the experiment on tracing the path of a ray of light through a rectangular glass slab, in which of the following experimental set-ups is a student likely to get best results? P1 and P2 are the positions of pins fixed by him.

(A) I

(B) II

(C) III

(D) IV


Observe the figure and write accurate conclusion regarding refraction of light.


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.


The diagram below shows a light source P embedded in a rectangular glass block ABCD of critical angle 42°. Complete the path of the ray PQ till it emerges out of the block. [Write necessary angles].


Is dispersion same as deviation?

Draw an í- `delta` graph for a mono chromatic raY through a glass prism of a plane and mark

(i) `delta` m, the angle of mínimum devíation

(íí) Any two values of i for which value of `delta` ís same.  


Can you guess the focal length of a plane mirror?

Choose the correct alternative and rewrite the following:

A glass slab is placed in the path of convergent light. The point of convergence of light


Rewrite the following statement by selecting the correct option:

If a ray of light strikes a glass slab at an angle of 600 with the surface of the slab, the angle of incidence must be __________________.


What should be the ratio of the speed of light through the liquid to the speed through the glass so that there is no refraction of light at the boundaries of the glass block when the system is illuminated by the light of one colour?


Light passes through a rectangular glass slab and through a triangular glass prism. In what way does the direction of the two emergent beams differ and why?


The speed of light in air is 3 × 10ms-1. Calculate the speed of light in water. The refractive index of water is 4/3.


The path of a ray of light coming from air passing through a rectangular glass slab traced by four students are shown as A, B, C and D in the figure. Which one of them is correct?

A B C D

A ray of light is incident at an angle of 45° on one face of a rectangular glass slab of thickness 10 cm and refractive index 3/2. Calculate the lateral shift produced ______.


Draw the ray diagram of a glass slab having medium A and B for the velocity of light ray VA and VB respectively and define Snell's law.

  1. If VB = 1.5 VA, then which medium is denser?
  2. What is the refractive index of A with respect to B?
  3. What is the refractive index of B with respect to A?

Observe the figure and name the ray AB, ray CD, ray GH.


Share
Notifications



      Forgot password?
Use app×