A horizontal power line at height 4 m carries 100 A current from East to West. The magnetic field directly below it on the ground is ( μ_0 = 4π × 10^- - Physics MCQ AIEEE 2026 | ExamTest.live

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A horizontal power line at height 4 m carries 100 A current from East to West. The magnetic field directly below it on the ground is (μ_{0} = 4 π \times 1 0^{- 7} Tm/A):

Solution & Step-by-step Explanation

Magnetic field due to a long straight wire: B = \frac{μ _{0} I}{2 π r} . B = \frac{4 π \times 1 0 ^{- 7} \times 100}{2 π \times 4} = \frac{2 \times 1 0 ^{- 5}}{4} = 5 \times 1 0^{- 6} T Direction using Right Hand Thumb Rule: Current is East to West. Below the wire, the field lines point towards the South.

Try it yourself before checking the explanation above.

A horizontal power line at height 4 m carries 100 A current from East to West. The magnetic field directly below it on the ground is (μ_{0} = 4 π \times 1 0^{- 7} Tm/A):

2.5 \times 1 0^{- 7} T southward

5 \times 1 0^{- 6} T northward

5 \times 1 0^{- 6} T southward

2.5 \times 1 0^{- 7} T northward

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