JEE Main · 2023 · 25 Jan 2023 · Shift 2 · Magnetic Effects of Current

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Two long parallel wires carrying currents 8 A and 15 A in opposite directions are placed at a distance of 7 cm from each other. A point P is at equidistant from both the wires such that the lines joining the point P to the wires are perpendicular to each other. The magnitude of magnetic field at P is

____

\times 1 0^{- 6} T

. (Given :

2 = 1.4

)

Answer: 68

Solution

Because the lines from P to the two wires meet at a right angle and P is the same distance from each, that distance follows from

7^{2} = d^{2} + d^{2}

, giving

d = \frac{7}{2} cm

. Each wire sets up a field perpendicular to its own line to P, so the two contributions are themselves at right angles and combine in quadrature:

B = \frac{μ _{0}}{2 π d} i_{1}^{2} + i_{2}^{2}

. With

8^{2} + 1 5^{2} = 17

B = \frac{( 2 \times 1 0 ^{- 7} ) 2}{7 \times 1 0 ^{- 2}} \times 17 = 68 \times 1 0^{- 6} T

JEE Main · 2023 · 25 Jan 2023 · Shift 2 · Integer answer

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JEE Main · 2023 · 25 Jan 2023 · Shift 2 · Magnetic Effects of Current

Solution

More JEE Main questions on Magnetic Effects of Current