Question

Two long parallel current carrying conductors $30\, cm$ apart having current each of $10\, A$ in same direction, then value of magnetic field at a point of $15 \,cm$ between them, from any of the wire.

• A. Zero
• B. $6 \times 10^{-5} T$
• C. $1.5 \times 10^{-5} T$
• D. $3 \times 10^{-5} T$

Answer 1

Answer: (A)

$\left|\vec{B}_{1}\right|=\left|\vec{B}_{2}\right|$

Also $\vec{ B }_{1}$ is into the plane and $\vec{ B }_{2}$ is out of the plane.
$\Rightarrow \vec{ B }_{\text {net }}=\text { zero }$