If current in two parallel wires flow in opposite directions, the force between the wires will:

Options

A. attractive
B. repulsive
C. zero
D. attractive or repulsive depending on the material of wires

Explanation

To solve the question regarding the force between two parallel wires carrying current in opposite directions, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Setup**: We have two parallel wires. Let's label them Wire 1 and Wire 2. The current in Wire 1 flows in one direction, while the current in Wire 2 flows in the opposite direction.

2. **Direction of Currents**: Assume the current in Wire 1 flows from left to right. Therefore, the current in Wire 2 flows from right to left.

3. **Magnetic Field Due to a Current-Carrying Wire**: A current-carrying wire generates a magnetic field around it. The direction of the magnetic field can be determined using the right-hand rule. For Wire 1, if you point your thumb in the direction of the current (left to right), your fingers will curl around the wire in a counter-clockwise direction.

4. **Magnetic Field at the Location of the Second Wire**: At the location of Wire 2 (to the left of Wire 1), the magnetic field created by Wire 1 will point into the page (or screen).

5. **Force on the Second Wire**: According to the Lorentz force law, a current-carrying wire placed in a magnetic field experiences a force. The direction of this force can also be determined using the right-hand rule. For Wire 2, which has current flowing from right to left, the magnetic field (from Wire 1) is into the page. Using the right-hand rule, the force on Wire 2 will be directed away from Wire 1.

6. **Conclusion**: Since the currents in the two wires are in opposite directions, the force between the two wires is repulsive. Therefore, the answer to the question is that the force between the wires will repel each other.

### Final Answer:
The force between the wires will repel each other.