Question

A wire is lying parallel to a square coil. Same current is flowing in same direction in both of them. The magnetic induction at any point P inside the coil will be :

• A. zero
• B. more than that produced by only coil
• C. less than that produced by only coil
• D. equal to that produced by only coil

Answer 1

The correct option is B more than that produced by only coil

$\overrightarrow{B_{QR}}=\overrightarrow{B_{SP}}$ and are $-\hat{k}$ direction.
$\overrightarrow{B_{PQ}}$ and $\overrightarrow{B_{RS}}$ are in $-\hat{k}$ direction.
Magnetic field due to the long wire is also in $-\hat{k}$ direction.
Since all are in the same direction, magnetic field at point P( center of the coil) is more than that produced by the coil.