Which of the following is incorrect statement

Options

A. A dimensionally correct equation may be correct
B. A dimensionally correct equation may be incorrect
C. A dimensionally incorrect equation may be correct
D. A dimensionally incorrect equation is incorrect

Answer

To determine which statement is incorrect, we need to analyze each of the four statements provided.

### Step-by-Step Solution:

1. **Statement 1: A dimensionally correct equation may be correct.**
- This statement is true. A dimensionally correct equation can indeed be correct, but it is not guaranteed to be so. For example, the equation for kinetic energy \( KE = mv^2 \) is dimensionally correct but not the correct formula, which is \( KE = \frac{1}{2} mv^2 \).

2. **Statement 2: A dimensionally correct equation may be incorrect.**
- This statement is also true. As mentioned in Statement 1, an equation can be dimensionally correct but still not represent the correct physical relationship.

3. **Statement 3: A dimensionally incorrect equation may be correct.**
- This statement is false. If an equation is dimensionally incorrect, it cannot be correct. For instance, if we take the equation for acceleration \( a = \frac{d}{t^2} \), this is dimensionally incorrect since the dimensions do not match (acceleration should have dimensions of \( LT^{-2} \)). Therefore, this statement is the incorrect one.

4. **Statement 4: A dimensionally incorrect equation is incorrect.**
- This statement is true. If an equation is dimensionally incorrect, it cannot represent a valid physical relationship, hence it is incorrect.

### Conclusion:
- The incorrect statement among the options is **Statement 3**: "A dimensionally incorrect equation may be correct."