Question

Assertion :A dam for water reservoir is built thicker at bottom than at the top. Reason: Pressure of water is very large at the bottom.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Wall of dams are thick from bottom because pressure of water at the bottom is very large due to the weight of the whole water stored up to a long height in the dam.

And we know pressure is given by

$Pressure=\frac{Force\left(Weight\right)}{Area}$

Pressure in inversely proportional to area.

So by making dam thick at bottom we increase area at bottom and more area mean very less pressure .This less pressure makes the dam structure safe otherwise the dam may collapse.

Hence, both reason and assertion are correct and reason is correct explanation of assertion.