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Question #42132
The Question
A cylindrical tank of constant cross-sectional area contains an ideal, incompressible liquid of density . At the bottom of the tank is a circular orifice made of a material with a coefficient of linear thermal expansion . The tank walls have zero thermal expansion. Initially (), the liquid is at a height above the orifice, and the orifice has an area such that . The system is heated such that the temperature of the orifice increases at a constant rate . Assuming the liquid density remains constant, find the initial rate of change of the efflux velocity of the liquid, .
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Variable_Constraint
Develop pure symbolic logic skills by mastering algebraic constraints without relying on numerical data.
Concepts Behind This Question
Expansion of Cavities in Solids|Torricelli’s Efflux Velocity|Differential Calculus
Why This Question Is Tricky
Common Mistakes
This problem tests the coupling of time-varying geometry with fluid dynamics.
A common JEE trap is assuming , which incorrectly simplifies Torricelli's law to and ignores the kinetic energy of the free surface.
Furthermore, students often fail to recognize that the efflux velocity is a multivariable function of both the falling fluid level and the thermally expanding orifice area .
Correctly solving the problem requires applying the multivariable chain rule to simultaneously account for the kinematic drop in pressure head and the thermal expansion of the cavity.
Quick Facts About This Question
Question Information
| Subject | Physics |
| Chapter | Thermal Properties of Matter - Class 11 Part 2 |
| Concept | Expansion of Cavities in Solids |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |