Which one of the following statements is wrong

Options

A. Young’s modulus for a perfectly rigid body is zero
B. Bulk modulus is relevant for solids, liquids and gases
C. Rubber is less elastic than steel
D. The Young’s modulus and shear modulus are relevant for solids

Explanation

To determine which statement is wrong, we need to analyze each of the given statements regarding elasticity:

1. **Jans modulus for a perfectly rigid body is 1.**
2. **The bulk modulus is irrelevant for solids, liquids, and gases.**
3. **Rubber is less elastic than steel.**
4. **Jans modulus and shear modulus are relevant for solids.**

### Step-by-Step Solution:

**Step 1: Analyze the first statement.**
- Jans modulus (Young's modulus) is defined as the ratio of stress (force per unit area) to strain (deformation per unit length). For a perfectly rigid body, the strain is zero when stress is applied, which leads to an undefined value for Jans modulus because it involves division by zero. Therefore, the statement that "Jans modulus for a perfectly rigid body is 1" is incorrect.

**Step 2: Analyze the second statement.**
- The bulk modulus is a measure of a material's resistance to uniform compression. It is relevant for solids, liquids, and gases. Therefore, the statement that "the bulk modulus is irrelevant for solid, liquid, and gases" is also incorrect.

**Step 3: Analyze the third statement.**
- Rubber is indeed less elastic than steel. This is true as steel has a higher Young's modulus compared to rubber, meaning steel can withstand more stress before deforming.

**Step 4: Analyze the fourth statement.**
- Both Jans modulus and shear modulus are relevant for solids. This statement is true as both moduli describe the elastic properties of solid materials.

### Conclusion:
The first statement is wrong: "Jans modulus for a perfectly rigid body is 1."