Statement-1: The stretching of a coil is determined by its shear modulus.
Statement-2: Shear modulus change only shape of a body keeping its dimensions unchanged.

Options

A. Statement-1, is true, Statement-2 is true, Statement-2 is correct explanation for statement-1
B. Statement-1 is true, statement-2 is true, statement-2 is NOT a correct explantion for statement-1
C. statement-1 is true, statement-2 is false
D. statement-1 is false statement-2 is true

Answer

To solve the question, we need to analyze both statements provided:

**Statement 1:** The stretching of a coil is determined by its shear modulus.

**Statement 2:** Shear modulus changes only the shape of a body, keeping its dimensions unchanged.

### Step-by-Step Solution:

1. **Understanding Shear Modulus:**
- The shear modulus (also known as the modulus of rigidity) is a measure of a material's ability to withstand shear deformation. It describes how a material deforms under shear stress.

2. **Analyzing Statement 1:**
- The stretching of a coil refers to how the coil changes when a force is applied. In the case of a coil, when it is stretched, it primarily undergoes a change in shape rather than a significant change in length.
- Therefore, the stretching of a coil is indeed influenced by its shear modulus, as it determines how much the coil can deform under shear stress.

3. **Analyzing Statement 2:**
- Statement 2 claims that shear modulus changes only the shape of a body while keeping its dimensions unchanged. This is accurate because shear deformation involves a change in shape (like twisting or shearing) without changing the overall dimensions (length and volume) of the material significantly.
- Thus, this statement correctly describes the behavior of materials under shear stress.

4. **Conclusion:**
- Both statements are true. Statement 1 is true because the stretching of a coil is indeed determined by its shear modulus. Statement 2 is also true as it correctly explains the nature of shear modulus in terms of shape change without altering dimensions.
- Since Statement 2 provides a correct explanation for Statement 1, we can conclude that both statements are true and Statement 2 is the correct explanation for Statement 1.

### Final Answer:
Both Statement 1 and Statement 2 are true, and Statement 2 is the correct explanation for Statement 1. Therefore, the correct option is A.

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