Question

The aim of experiment is to find the refractive index of prism write list of material required and steps of procedure​

Answer 1

Answer:

Procedure for finding the refractive index of a  glass prism and the materials required to make the experiment a success.

Explanation:

step 1 : collection of apparatus

For the experiment to be a success you will need the following apparatus;

Glass prism (60°)

white paper

protractor

A scale

Drawing pins

Drawing Board

A pencil

step 2 ; setting up of apparatus.

procedure;

• Fix the white paper on the drawing board tightly by fastening using the drawing pins.
• Draw the boundary of the prism.

• Draw the normal and the incident ray. (A normal ray is a ray that is incident perpendicularly on a surface. An incident ray the ray that strikes the surface before reflection.)

• fix two pins on the incident ray and look for the image of the two pins from the other side of the glass prism
• fix the third and forth pins such that the images of the first and second pin  are in a straight line
• Remove the third and fourth pin and encircle third plucks , draw a straight line through the plucks.
• Fain the emergent ray (An emergent ray is a ray that has been observed on the other side of the prism after refraction.)
• Draw   the refracted ray ( A refracted ray is a ray  extending onward from the point of refraction.) and the incident ray.

• follow previous steps to take new readings and record new observations

 Table

no. of trials            Angle of incidence                Angle of deviation

1.                                         30                                            58

2.                                        35                                             45

3.                                        40                                            42

4.                                        45                                            40

5.                                        50                                            46    

The angle of deviation simply refer to the angle through which a ray of light turns  from its original path after passing through a prism.

• From the result obtained , Draw a graph between angle of incidence and angle of deviation.( use the scale : horizonntal axis 10 divisions represents 10°, vertical axis 10 divisions represents 10°. )
• Pick the angle of minimum deviation ∠D

To find the refractive index n, of a glass prism of angle 60° (A) with the angle of minimum deviation as D, we use the following formulae;

                                  n = sin ( (A+D)/2) ÷ sin (A/2)

                        In our case D will be 40°  A will be  60° Therefore

                                         n=   sin (100/2)÷ sin (60/2)

                                           ≈ 1.53

  Hence the refractive index of our particular glass prism will be 1.53 . Remember the refractive index has no units since it is a ratio between the velocity of light in a vacuum and the velocity of light in a medium.

Goodluck!

Answer 2

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