While opening a tap with two fingers, the forces applied are

Options

A. equal in magnitude
B. parallel to each other
C. opposite in direction
D. all of these

Explanation

To solve the question regarding the forces applied while opening a tap with two fingers, we can break down the reasoning step by step.

### Step-by-Step Solution:

1. **Understanding the Problem**: We need to analyze the forces applied by two fingers when opening a tap. The goal is to achieve efficient rotation of the tap without any unnecessary translational motion.

2. **Identifying the Forces**: Let’s denote the forces applied by the two fingers as F1 and F2. Since we are using two fingers, these forces will be applied at different points on the tap.

3. **Torque and Rotation**: For efficient rotation, the torques produced by these forces must add up. If one finger applies a force in a clockwise direction, the other must also apply a force in the same direction (clockwise) or both must apply forces in the opposite direction (anti-clockwise) to ensure that the torques are additive.

4. **Condition for No Net Force**: To avoid any translational motion (where the tap would move sideways instead of rotating), the vector sum of the forces must equal zero. This means that F1 + F2 = 0, which implies that F1 and F2 must be equal in magnitude but opposite in direction.

5. **Magnitude of Forces**: Since the forces must be equal in magnitude to cancel each other out, we can say |F1| = |F2|. This ensures that there is no net force acting on the tap, allowing it to rotate efficiently.

6. **Direction of Forces**: Although the forces are equal in magnitude, they are applied at different points on the tap. Therefore, they cannot be collinear (i.e., they cannot lie on the same straight line). Instead, they must be parallel and opposite to each other.

7. **Conclusion**: Based on the analysis, we can conclude that the forces applied by the two fingers are equal in magnitude, opposite in direction, and parallel to each other. Therefore, the most appropriate option is that all three conditions are satisfied.

### Final Answer:
The forces applied while opening a tap with two fingers are equal in magnitude, opposite in direction, and parallel to each other. Thus, the correct option is option 4.