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Statement-1: The free surface of a liquid that is at rest relative to its stationary container is always perpendicular to the direction of g (gravity). Statement-2: A liquid in equilibrium cannot sustain any shear stress.
- Statement-1 is true, Statement-2 is true, and Statement-2 is the correct explanation of Statement-1.
- Statement-1 is true, Statement-2 is true, but Statement-2 is NOT the correct explanation of Statement-1.
- Statement-1 is true, Statement-2 is false.
- Statement-1 is false, Statement-2 is true.
Correct answer: Statement-1 is true, Statement-2 is true, and Statement-2 is the correct explanation of Statement-1.
Solution
A liquid at rest cannot support shear stress. If the free surface were not perpendicular to gravity, the component of gravity along the surface would be unbalanced and the liquid would flow. Equilibrium therefore requires the surface to be normal to g. Statement-2 is the reason for Statement-1.
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