The figure given below shows a long, straight, solid wire of circular cross-section of radius \(a\) carrying a steady current \(I.\) The current \(I\) is uniformly distributed across its cross-section. The plot which correctly represents the variation of the magnetic field \((B)\) with distance \((r)\) from the axis of the conductor in the region is:
1. 2.
3. 4.
Subtopic:  Ampere Circuital Law |
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Level 2: 60%+
NEET - 2026
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From Ampere's circuital law, for a long straight wire of circular cross-section carrying a steady-current, the variation of the magnetic field inside and outside the region of the wire is:
1. A linearly decreasing function of distance upto the boundary of the wire and then a linearly increasing one for the outside region.
2. Uniform and remains constant for both regions.
3. A linearly increasing function of distance upto the boundary of the wire and then a linearly decreasing one for the outside region.
4. A linearly increasing function of distance \(r\) upto the boundary of the wire and then decreasing one with \(1/r\) dependence for the outside region.
Subtopic:  Ampere Circuital Law |
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Level 2: 60%+
NEET - 2022
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A thick current-carrying cable of radius '\(R\)' carries current \('I'\) uniformly distributed across its cross-section. The variation of magnetic field \(B(r)\) due to the cable with the distance '\(r\)' from the axis of the cable is represented by:

1.   2.
3. 4.
Subtopic:  Ampere Circuital Law |
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Level 1: 80%+
NEET - 2021
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A cylindrical conductor of radius \(R\) is carrying a constant current. The plot of the magnitude of the magnetic field \(B\) with the distance \(d\) from the centre of the conductor is correctly represented by the figure:

1. 2.
3. 4.
Subtopic:  Ampere Circuital Law |
 70%
Level 2: 60%+
NEET - 2019
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Two toroids \(1\) and \(2\) have total no. of turns \(200\) and \(100\) respectively with average radii \(40~\text{cm}\) and \(20~\text{cm}\) respectively. If they carry the same current \(i,\) what will be the ratio of the magnetic fields along the two loops?
1. \(1:1\)
2. \(4:1\)
3. \(2:1\)
4. \(1:2\)

Subtopic:  Ampere Circuital Law |
 80%
Level 1: 80%+
NEET - 2019
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