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Assertion : For the sensitivity of a cam...

Assertion `:` For the sensitivity of a camera, its aperture should be reduced
Reason `:` Smaller the aperture, image focussing is also sharp.

A

If both the assertion and reason are true and the reason is the correct explanation of the assertion.

B

If both assertion and reason are true but reason is not the correct explanation of the assertion.

C

If assertion is true but reason is false.

D

If the assertion and reason both are false.

Text Solution

Verified by Experts

The correct Answer is:
C

Very large apertures gives blurred images because of aberrations. By reducing the aperture the clear image is obtained and thus the sensitivity of camera increases.
Also the focussing of object at different distance is achieved by slightly altering the separation of the lens from the film .
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A2Z-GEOMETRICAL OPTICS-Section D - Chapter End Test
  1. When the distance between the object and the screen is more than 4 f....

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  2. a convex lens of power +6 diopter is placed in contact with a concave ...

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  3. A concave lens of focal length 20 cm product an image half in size of ...

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  4. A convex lens of focal length 1.0m and a concave lens of focal length ...

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  5. If in a planoconvex lens, the radius of curvature of the convex surfac...

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  6. A convex lens A of focal length 20cm and a concave lens G of focal le...

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  7. The radii of curvature of the two surfaces of a lens are 20cm and 30 c...

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  8. A lens forms a virtual image 4 cm away from it when an object is place...

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  9. A concave lens of focal length (1)/(3)m forms a real, inverted image t...

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  10. An object is placed at a distance of f//2 from a convex lens. The imag...

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  11. The graph shows how the magnification m produced by a convex thin len...

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  12. A convex lens forms an image of an object placed 20cm away from it at ...

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  13. A converging lens is to projected image of a lamp 4 times the size of ...

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  14. A thin lens produces an upright image of the same size as the object. ...

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  15. A convex lens of focal length 10cm and concave lens of focal length 20...

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  16. The focal lengths of the objective and eye- lens of a microscope are 1...

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  17. A microscope has an objective of focal length 1.5 cm and eye piece of ...

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  18. An equiconvex lens is cut into two halves along (i) XOX^(') and (ii) Y...

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  19. Assertion : For the sensitivity of a camera, its aperture should be re...

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  20. Assertion : The mirrors used in search lights are parabolic and not co...

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