Which of the following statements is true? - Science

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MCQ

Which of the following statements is true?

Options

  • A convex lens has 4 dioptre power having a focal length 0.25 m

  •  A convex lens has –4 dioptre power having a focal length 0.25 m

  • A concave lens has 4 dioptre power having a focal length 0.25 m

  • A concave lens has –4 dioptre power having a focal length 0.25 m

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Solution

A convex lens has 4 dioptre power having a focal length 0.25 m

Explanation -

The focal length and the power of concave lens is always negative and of convex lens is positive. The relation between power and focal length is,  `"P" = 1/"f"`

Using this formula to find power,

`"P" = 1/"f"`

`= 1/0.25`

= 4D

Concept: Convex Lens
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Chapter 10: Light – Reflection and Refraction - Multiple Choice Questions [Page 80]

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NCERT Exemplar Science Class 10
Chapter 10 Light – Reflection and Refraction
Multiple Choice Questions | Q 8. | Page 80

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