Assertion: The flow is turbulent for Reynolds number greater than `2000`
Reason: Turbulence dissipates kinetic energy in the form of heat.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true and reason is false.
D. If both assertion and reason are false.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that "The flow is turbulent for Reynolds number greater than 2000."
- The Reynolds number (Re) is a dimensionless quantity used to predict flow patterns in different fluid flow situations.
- A Reynolds number greater than 2000 typically indicates that the flow is turbulent. Therefore, this assertion is **true**.

### Step 2: Understand the Reason
The reason states that "Turbulence dissipates kinetic energy in the form of heat."
- Turbulent flow is characterized by chaotic and irregular fluid motion, which leads to energy dissipation due to friction and viscosity within the fluid layers.
- This dissipation of kinetic energy can indeed result in the conversion of kinetic energy into thermal energy (heat). Thus, this reason is also **true**.

### Step 3: Analyze the Relationship Between Assertion and Reason
Now we need to determine if the reason correctly explains the assertion.
- While both the assertion and reason are true, the reason does not directly explain why the flow becomes turbulent at a Reynolds number greater than 2000. The assertion is based on empirical observations and definitions, while the reason describes a consequence of turbulence rather than the cause of it.

### Conclusion
Since both the assertion and the reason are true, but the reason does not explain the assertion, the correct answer is **Option B**: Both the assertion and reason are true, but the reason does not explain the assertion.

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