Two identical coils A and B are kept on a horizontal tube side by side without touching each other. If the current in the coil A increases with time, in response, the coil B

Options

A. is attracted by A
B. remains stationary
C. is repelled
D. rotates

Explanation

To solve the problem, we need to analyze the situation involving two identical coils, A and B, and how they interact when the current in coil A changes.

### Step-by-Step Solution:

1. **Understand the Setup**:
- We have two identical coils, A and B, placed side by side on a horizontal tube without touching each other.

2. **Current in Coil A**:
- It is given that the current in coil A increases with time.

3. **Magnetic Field Due to Coil A**:
- When the current in coil A increases, it generates a magnetic field around it. The strength and direction of this magnetic field depend on the magnitude and direction of the current flowing through coil A.

4. **Change in Magnetic Field**:
- As the current increases, the magnetic field around coil A also changes. According to Faraday's law of electromagnetic induction, a changing magnetic field can induce an electromotive force (EMF) in a nearby conductor.

5. **Induction in Coil B**:
- The changing magnetic field from coil A induces an electric current in coil B. This phenomenon is known as electromagnetic induction.

6. **Direction of Induced Current in Coil B**:
- According to Lenz's law, the direction of the induced current in coil B will be such that it opposes the change in magnetic flux through it. Since the magnetic field from coil A is increasing, the induced current in coil B will flow in a direction that creates a magnetic field opposing the increase.

7. **Interaction Between Coils A and B**:
- Since both coils are identical and the induced current in coil B flows in the opposite direction to the current in coil A, the two coils will experience a force due to the interaction of their magnetic fields.

8. **Conclusion**:
- The induced current in coil B will flow in the opposite direction to the current in coil A, resulting in a repulsive force between the two coils. Therefore, coil B will repel coil A.

### Final Answer:
When the current in coil A increases, coil B will experience an induced current that flows in the opposite direction, causing coil B to repel coil A.

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