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Evaluation

Cloze Activity

Read the paragraph below and fill in the missing words.

Total internal reflection, critical angle and refractive index.

As the angle of incidence in the denser medium increases, the angle of refraction also If this continues until the angle of refraction reaches , the angle of incidence is called the C. A critical angle is defined as the angle of in the denser medium for which the angle of refraction is in the less dense medium.

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DropDown Activity- To show how to calculate refractive index using the critical anle

Read and complete -

The paragraph below

By the principle of the reversibility of light,

aηg= sin900/sin C =1/sin C.

n=1/ .

If the angle of incidence exceeds the angle, the light undergoes total internal . This reflection obeys all the laws of reflection.

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Multi-select -

Question

Select all those statements which explain the conditions necessary for total internal reflection to occur.

Answers

Light must pass from an optically denser medium to a less optically dense medium

Light must pass from a less optically denser medium to an optically dense medium

  • The angle of incidence in the denser medium must be less than the critical angle.

  • The angle of incidence in the denser medium must be greater than the critical angle.

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True-False Question

study the following statements or equations and state whether it is true or false.

Question 1

n=sin i/sin c=real depth/apparent depth=1/ sin c=velocity in vacuum/velocity in a medium

Question 2

All these are examples applications of total internal reflection: mirage , optical fibre, formation of rainbow, prism periscope. Is it true or false?

Question 3

Total internal reflection occurs when a ray of light moves from a rarer to a denser medium. Is it true or false?

SCORM Quiz- summary questions- choose one correct answer

Question

 The ratio of sine of angle of incidence to the sine of angle of refraction is a constant for a given pair of media. What is the name of this law?

Answers

Hooke's law

Snell's law

Fleming's law

Newton's second law

Question

A prism periscope has the following advantages over the simple periscope:

Answers

Forms brighter and clearer images

Does not absorb the energy of the light

Has a tough structure and thus does not easily wear

None of the above

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