A coil carrying a heavy current and having large number of turns mounted in a N-S vertical plane and current flow in clockwise direction. A small magnetic needle at its center will have its north pole in

Options

A. East -north direction
B. West-north direction
C. East-south direction
D. West-south direction

Answer

To solve the problem, we need to determine the direction of the magnetic field produced by a coil carrying a current in a specific direction. Here are the steps to find the answer:

### Step 1: Understand the Setup
We have a coil with a large number of turns, and it is oriented in a north-south vertical plane. The current flows in a clockwise direction when viewed from the north.

### Step 2: Apply the Right-Hand Rule
To find the direction of the magnetic field produced by the coil, we can use the right-hand rule for coils. According to this rule, if you curl the fingers of your right hand in the direction of the current flow, your thumb will point in the direction of the magnetic field inside the coil.

### Step 3: Determine the Magnetic Field Direction
Since the current is flowing in a clockwise direction when viewed from the north, if we apply the right-hand rule:
- Curl your fingers in the direction of the current (clockwise).
- Your thumb will point downwards, indicating that the magnetic field inside the coil is directed downwards.

### Step 4: Analyze the Magnetic Needle
A small magnetic needle has a north and south pole. The north pole of a magnetic needle will align itself with the magnetic field lines. Since the magnetic field inside the coil is directed downwards, the north pole of the magnetic needle will point downwards.

### Step 5: Conclusion
Thus, the north pole of the small magnetic needle at the center of the coil will point downwards.

### Final Answer
The north pole of the small magnetic needle will be directed downwards.

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