Question

Find net magnetic field at point P ?

• A. $2\sqrt{3}\times {10}^{-5}T$
• B. $\sqrt{3}\times {10}^{-5}T$
• C. $\sqrt{\frac{3}{2}}\times {10}^{-5}T$
• D. $3\sqrt{3}\times {10}^{-5}T$

Answer 1

The correct option is A $2\sqrt{3}\times {10}^{-5}T$

Distance (r) of point P from wire is 8 cm (By pythagoras theorem)
$B_{net}=2Bcos\theta =2Bcos{30}^0$
$=2\times 2\times \frac{\sqrt{3}}{2}\times \frac{{\mu }_{0}i}{2\pi r}$
$=\frac{4\times {10}^{-7}\times 4\sqrt{3}}{8\times {10}^{-2}}=2\sqrt{3}\times {10}^{-5}T$