Physics - Magnetism Question with Solution | TestHub

$\mathrm{\varphi }=\overrightarrow{\mathrm{B}}.\overrightarrow{\mathrm{A}}$

The area vector$\overrightarrow{\mathrm{A}}$is perpendicular to the surface. So, when the surface is parallel to the magnetic field, the angle between$\overrightarrow{\mathrm{B}}$and$\overrightarrow{\mathrm{A}}$is$90°$.

Hence$\mathrm{\varphi }=0$.