A coil carrying a heavy current and having large number of turns mounted in a N-S vertical plane and

Question

A coil carrying a heavy current and having large number of turns mounted in a N-S vertical plane and a current flows in the clock-wise direction while looking from east. A small magnetic needle at its centre will have its north pole in\

Professor PC Thomas Classes · Answer

Earths field $\mathrm{B}_{\mathrm{H}}$ is north wards. Current in the coil is clockwise when looking from east. Hence eastern side is south pole and western side north pole. So the field $B$ due to the coil is towards the west. The resultant of $B$ and $B_{H}$ will be between west and north. So the pivoted needle will point between west and north.\