166. In the human eye, the focussing is done by

1. 1. To and fro movement of the eye lens

   
   
   

   2. To and fro movement of the retina

   
   
   

   3. Change in the convexity of the eye lens

   
   
   

   4. Change in the refractive index of the eye fluids

   
   
   

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   N/A

   Correct Option: C

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167. A light wave travelling in a transparent homogeneous medium enters another homogeneous transparent medium of higher refractive index. The speed of light in the second medium

1. 1. Is less than that in the first medium

   
   
   

   2. Is more than that in the first medium

   
   
   

   3. Is the same as that in the first medium

   
   
   

   4. May be more or less than that in the first medium depending on the angle of incidence

   
   
   

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   N/A

   Correct Option: A

   N/A

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168. Rainbow is formed due to a combination of

1. 1. Dispersion and total internal reflection

   
   
   

   2. Refraction and absorption

   
   
   

   3. Dispersion and focussing

   
   
   

   4. Refraction and scattering

   
   
   

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   N/A

   Correct Option: A

   N/A

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169. Consider the following statements
     1. Compound microscope has an objective lens with a very short focal length
     2. Simple microscope consists of a strong converging lens system
     3. Television camera converts the optical images into electrical video signals
     4. Hypermetropia is corrected by using a diverging lens. Which of theses statement is / are correct ?
     Codes

1. 1. 4 only

   
   
   

   2. 2 and 3

   
   
   

   3. 1, 2 and 3

   
   
   

   4. 1. 2. 3. and 4

   
   
   

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   N/A

   Correct Option: C

   N/A

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170. Different objects at different distances are seen by the eye. The parameter that remains constant is

1. 1. The focal length of the eye lens

   
   
   

   2. The object distance from the eye lens

   
   
   

   3. The radii of curvature of the eye lens

   
   
   

   4. The image distance from the eye lens

   
   
   

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1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: D

   N/A

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