Two parallel forces not having the same line of action form a couple if they are

Options

A. like and unequal
B. like and equal
C. unequal and unlike
D. equal and unlike

Answer

To solve the question, we need to determine under what conditions two parallel forces that do not have the same line of action can form a couple. Let's break it down step by step.

### Step-by-Step Solution:

1. **Understanding the Definition of a Couple**:
A couple consists of two equal and opposite forces that act on an object but do not share the same line of action. The forces create a rotational effect without translating the object.

2. **Identifying the Characteristics of Forces**:
- The forces must be equal in magnitude.
- The forces must be opposite in direction (unlike).
- The forces must not be parallel (they should act in different lines of action).

3. **Analyzing the Given Options**:
The question provides four options:
- Like and unequal
- Like and equal
- Equal and unlike
- None

4. **Evaluating Each Option**:
- **Like and unequal**: This cannot form a couple because they are not opposite.
- **Like and equal**: This cannot form a couple because they are not opposite.
- **Equal and unlike**: This can form a couple because they are equal in magnitude and opposite in direction.
- **None**: This is not applicable since we have found a valid option.

5. **Conclusion**:
The correct answer is that two parallel forces not having the same line of action form a couple if they are **equal and unlike**.

### Final Answer:
The correct option is **Equal and unlike**.

---