When two co-axial coils having same current in same direction are bring to each other, then the value of current in both coils:

Options

A. increases
B. decreases
C. first increases and then decreases
D. remain same

Explanation

To solve the problem of what happens to the current in two coaxial coils when they are brought closer together with the same current flowing in the same direction, we can follow these steps:

### Step 1: Understand the Setup
We have two coaxial coils (Coil 1 and Coil 2) that are aligned along the same axis and are carrying the same current (I1 = I2). The currents in both coils are flowing in the same direction.

**Hint:** Remember that coaxial coils are aligned along the same axis, which affects how their magnetic fields interact.

### Step 2: Analyze the Magnetic Field
When current flows through a coil, it generates a magnetic field. The direction of the magnetic field produced by each coil can be determined using the right-hand rule. Since both coils carry current in the same direction, their magnetic fields will reinforce each other when they are brought closer.

**Hint:** Use the right-hand rule to visualize the direction of the magnetic fields created by each coil.

### Step 3: Consider the Effect of Bringing the Coils Closer
As the coils are brought closer together, the magnetic flux through each coil changes. According to Faraday's law of electromagnetic induction, a change in magnetic flux through a coil induces an electromotive force (emf) in that coil.

**Hint:** Recall that a change in magnetic flux can induce an emf, which can lead to an induced current.

### Step 4: Determine the Direction of Induced Current
The induced current will flow in a direction that opposes the change in magnetic flux through the coil, as stated by Lenz's law. Since the coils are bringing their magnetic fields closer together, the induced current will oppose the original current flowing in the coils.

**Hint:** Lenz's law states that the induced current will always oppose the change that produced it.

### Step 5: Conclusion on Current Values
As a result of the induced current opposing the original current, the net current in both coils will decrease. Therefore, when the two coils are brought closer together, the value of the current in both coils will decrease.

**Hint:** The net effect of the induced current is to reduce the original current in each coil.

### Final Answer
The value of the current in both coils will decrease when they are brought closer together.