Concept:The magnetic field strength created by a long straight current-carrying wire is inversely proportional to the radial distance from the wire. Visually, stronger fields are represented by lines closer together.
Formula:$$ B = \frac{\mu_0 I}{2\pi r} $$
Solution:- Observe the formula: \( B \propto \frac{1}{r} \). As distance \( r \) increases, the magnetic field strength \( B \) decreases.
- In field line diagrams, a weaker field is depicted by field lines that are spaced further apart.
- Therefore, as you move away from the conductor, the distance between the consecutive magnetic field lines increases.
Why other options are incorrect:Option B implies the field gets weaker near the wire, which is false. Option C implies the field gets stronger away from the wire. Option D implies a complex oscillatory field which doesn't apply to a straight DC wire.
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