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Two long parallel wires P and Q are both perpendicular to the plane of the paper with distance of 5 m between them. If P and Q carry currents of 2.5 amp and 5 amp respectively in the same direction, then the magnetic field at a point half-way between the wires is
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3μ0 2π -
μ0 π -
√3μ0 2π -
μ0 π
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Correct Option: D
When the current flows in both wires in the same direction then magnetic field at half way due to the wire P,
| →B'p = | = | = | (where I1 = 2.5 amp) | ||||
| 2π | π5 | π2 | |||||
| 2 |
The direction of ⇒B'p is downward ⊙
Magnetic field at half way due to wire Q
| →B'Q = | = | [upward ⊗] | |||
| 2π | π | ||||
| 2 |
[where I2 = 2.5 amp]
Net magnetic field at half way
→B' = →B'P + →B'Q
| = - | + | = | (upward) | |||
| 2π | π | 2π |
| Hence, net magnetic field at midpoint = | |
| 2π |
