Assertion : Bulk modulus of elasticity can be defined for all three states of matter, solid liquid and gas.
Reason: Young's modulus is not defined for liquids and gases.

Options

A. (a) If both Assertion and Reason are true and the Reason is correctn explanation of the Assertion.
B. (b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C. If Assertion is true, but the Reason is false.
D. If Assertion is false but the Reason is true.

Explanation

To analyze the given assertion and reason, we will break down the statements step by step.

### Step 1: Understanding the Assertion
**Assertion:** Bulk modulus of elasticity can be defined for all three states of matter: solid, liquid, and gas.

- **Explanation:** The bulk modulus of elasticity (K) measures a material's response to uniform pressure applied in all directions, which results in a change in volume. Since solids, liquids, and gases can all undergo volume changes when subjected to pressure, the bulk modulus can indeed be defined for all three states of matter.

### Step 2: Understanding the Reason
**Reason:** Young's modulus is not defined for liquids and gases.

- **Explanation:** Young's modulus (Y) measures the tensile or compressive stress and strain in materials, specifically relating to changes in length. Solids can experience changes in length when subjected to tensile or compressive forces, which is why Young's modulus is applicable to solids. However, liquids and gases do not have a fixed shape and cannot sustain shear stress, thus Young's modulus is not defined for them.

### Step 3: Evaluating the Relationship Between Assertion and Reason
- The assertion is true because bulk modulus applies to all three states of matter.
- The reason is also true, as Young's modulus is indeed not applicable to liquids and gases.

### Step 4: Conclusion
While both the assertion and reason are true, the reason does not correctly explain the assertion. Therefore, the correct answer is that the assertion is true, and the reason is true, but the reason is not the correct explanation for the assertion.

### Final Answer:
- **Assertion:** True
- **Reason:** True
- **Explanation:** The reason provided does not correctly explain why the assertion is true.

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