Identify the correct statement bout the magnetic field lines.

Options

A. These start always from closed loops
B. These lines always form closed loops
C. Both a and b are correct
D. Both a and b are wrong

Explanation

To solve the question "Identify the correct statement about the magnetic field lines," we will analyze the statements provided and determine which one is true based on our understanding of magnetic field lines.

### Step-by-Step Solution:

1. **Understanding Magnetic Field Lines**:
Magnetic field lines are visual representations of the magnetic field around a magnet. They indicate the direction and strength of the magnetic field.

2. **Analyzing the Statements**:
- **Statement A**: "They always start from closed loops."
- This statement is incorrect. Magnetic field lines do not have a starting point; they emerge from the north pole of a magnet and enter the south pole, forming closed loops.

- **Statement B**: "They always form closed loops."
- This statement is correct. Magnetic field lines indeed form closed loops, meaning they go from the north pole to the south pole and then continue inside the magnet back to the north pole.

- **Statement C**: (Assuming it states something incorrect about the nature of magnetic field lines).
- **Statement D**: (Assuming it states something incorrect about the nature of magnetic field lines).

3. **Conclusion**:
Based on the analysis, the only correct statement about magnetic field lines is Statement B: "They always form closed loops."

### Final Answer:
The correct statement about the magnetic field lines is: **They always form closed loops.**

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