Question

Two infinite long current carrying wires A and B are placed as shown in figure. Each wire carries same current $ I $ . The resultant magnetic field intensity at point P is

• A. $ \frac{{{\mu }_{0}}I}{2\pi a} $
• B. $ \frac{\sqrt{2}{{\mu }_{0}}I}{2\pi a} $
• C. $ \frac{{{\mu }_{0}}I}{2\sqrt{2}\pi a} $
• D. $ \frac{{{\mu }_{0}}I}{4\sqrt{2}\pi a} $

Answer 1

Answer: (A)

$ {{B}_{A}}={{B}_{B}}=\frac{{{\mu }_{0}}I}{2\pi \times \sqrt{2}a} $
So, $ B=\sqrt{B_{A}^{2}+B_{B}^{2}}=\frac{{{\mu }_{0}}I}{2\pi a} $