Question

A dam for water reservoir is built thicker at the bottom than at the top because

• A. Pressure of water is very large at the bottom due to its large depth
• B. Water is likely to have more density at the bottom due to its large depth
• C. Quantity of water at the bottom is large
• D. Variation in value of g

Answer 1

The correct option is A Pressure of water is very large at the bottom due to its large depth

The pressure in the liquid is given as,

$P=h\rho g$

where, h is depth inside liquid,

$\rho$ is density of liquid and g is acceleration due to gravity.

Thus the pressure in the liquid increases with depth.

Therefore dam for water reservoir is built thicker at the bottom since, pressure of the water is much more deeper down at ground level so that it is strong enough to withstand the large pressure.

Hence, option A is correct answer.