Question

Two long parallel wires $P$ and $Q$ are held perpendicular to the plane of the paper at a acceptance of $5m$ between them. If $P$ and $Q$ carry currents of $2.5$ and $5amp$ respectively in the same direction, then the magnetic field at a point half way between the wire is

• A. $\frac{{\mu }_0}{\pi }$
• B. $\frac{\sqrt{3}{\mu }_0}{\pi }$
• C. $\frac{{\mu }_0}{2\pi }$
• D. $\frac{3{\mu }_0}{2\pi }$

Answer 1

The correct option is C $\frac{{\mu }_0}{2\pi }$

$BP=\frac{lw}{2A}.\frac{2.5A}{2.5M}$

$=\frac{lw}{2\pi }$ unit

$BP=\frac{lw}{2\pi }.\frac{5A}{2.5M}=\to \frac{lw}{2\pi }$ unit

Net field $=BP+BG=-\frac{lw}{2\pi }$ unit

Value $=\frac{lw}{2\pi }$ unit