Assertion : The elastic spring force arises due to the net attraction or repulsion between the neighbouring atoms of the spring when it is elongated of compressed.
Reason : The laws of derived forces such as spring force, friction force are independent of the laws of fundamental forces in nature.

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 but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the assertion and reasoning question, we will analyze both the assertion and the reason step by step.

### Step 1: Analyze the Assertion
The assertion states: "The elastic spring force arises due to the net attraction or repulsion between the neighboring atoms of the spring when it is elongated or compressed."

**Explanation:**
- When a spring is either stretched (elongated) or compressed, the atoms within the spring experience changes in their distances from each other.
- This change in distance leads to either an increase or decrease in the intermolecular forces (attraction or repulsion) between the neighboring atoms.
- As a result, these forces generate a restoring force that acts to return the spring to its original shape when the external force is removed.

**Conclusion for Assertion:**
- The assertion is **true** because the elastic spring force indeed arises from the interactions between neighboring atoms when the spring is deformed.

### Step 2: Analyze the Reason
The reason states: "The laws of derived forces such as spring force, friction force are independent of the laws of fundamental forces in nature."

**Explanation:**
- Derived forces, such as spring force and friction force, are not independent of fundamental forces. Instead, they are manifestations of the underlying fundamental forces (like electromagnetic forces).
- The behavior of springs and friction is ultimately governed by the fundamental interactions at the atomic and molecular levels.
- Therefore, the statement that derived forces are independent of fundamental forces is incorrect.

**Conclusion for Reason:**
- The reason is **false** because derived forces are indeed dependent on the fundamental forces in nature.

### Final Conclusion
- The assertion is true, while the reason is false. Therefore, the correct answer is that the assertion is true, and the reason is false.

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