186. In a compound microscope cross wires are fixed at the point

1. 1. Where the image is formed by the objective

   
   
   

   2. Where the image is formed by the eye piece

   
   
   

   3. Where the focal point of the objective lies

   
   
   

   4. Where the focal point of the eye piece lies

   
   
   

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   N/A

   Correct Option: A

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187. Optical fibres are based on

1. 1. Scattering

   
   
   

   2. Refraction

   
   
   

   3. Total internal reflection

   
   
   

   4. All of these

   
   
   

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   N/A

   Correct Option: C

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188. The phenomenon of splitting white light into seven colours is called

1. 1. Reflection

   
   
   

   2. Refraction

   
   
   

   3. Refractive index

   
   
   

   4. Dispersion

   
   
   

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   N/A

   Correct Option: D

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189. Which of the following types of light are strongly absorbed by plants ?

1. 1. Violet and orange

   
   
   

   2. Blue and red

   
   
   

   3. Indigo and yellow

   
   
   

   4. Yellow and violet

   
   
   

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   N/A

   Correct Option: B

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190. A compound microscope has a magnification of 30. The focal length of eye piece is 5 cm. If the final image is formed at the least distance of distinct vision (25 cm) the magnification produced by the objective is

1. 1. 5

   
   
   

   2. 7.5

   
   
   

   3. 10

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: A

   N/A

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