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A: The bridges declared unsafe after a l...

A: The bridges declared unsafe after a long use.
R: Elastic strength of bridges increase with time.

A

Both are true and the reason is the correct explanation of the assertion.

B

Both are true but the reason is not correct explanation of the assertion.

C

Assertion is true, but the reason is false.

D

Both assertion and reason are false.

Text Solution

Verified by Experts

The correct Answer is:
C
Assertion is true but reason is false.
Elastic strength of bridges decreases with time.
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KUMAR PRAKASHAN-MACHANICAL PROPERTIES OF SOLIDS -SECTION-C
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  2. Breaking stress is known as elasticity.

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  3. Quartxz is almost elastic body.

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  4. What is shear modulus for liquid ?

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  5. For a given load (external force) steel is more deformed than rubber.

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  6. When solid body beated, roled, heated or cooled its elastic properties...

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  7. Young's modulus of rigid body is …….

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  8. A wire increase by 10 ^(-6) times its original length when a stress o...

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  9. The value of Poisson's ratio for steel is ……..

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  10. If a body breaks immediately after the elastic limit then this body is...

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  11. An elastic body which can be stretched to cause arge strains are calle...

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  12. Column-II is related to Column-I. join them appropriately :

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  13. Join details of Column-II with given information in Column-I appropria...

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  14. In column-I there are two graphs and in Column-II whose graph is for t...

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  15. Join the relation of physical quantities in Column-I to the details gi...

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  16. A: Two wire A and B having equal cross sections made from the same mat...

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  17. A: The stretching of a coil is determined by the shear modulus. R: S...

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  18. A: Rubber is less elastic than steel. R: Under given deforming force...

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  19. A: The bridges declared unsafe after a long use. R: Elastic strength...

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  20. A: A thread of length L is streatched by a force of 5N, its length inc...

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